Overview Of Grade 8 Curriculum

Overview of Grade 8 Curriculum Motion and Forces

“What Makes an Object’s Motion Change?”

“How Can I Explain and Predict Motion?”

The eighth grade curriculum has three strands that help complete the middle school learning progression in the study of motion and forces. They aim to help students answer the overarching questions about motion and forces that are listed above. The first strand, Investigating Motion: Position, Speed and Velocity, helps students distinguish between position, speed and velocity and it aims to have students more accurately describe one dimensional motion. Students learn the significance of accurately and completely describing motion. The second strand, Investigating Changes in Motion, focuses on the three ways an object can accelerate. Students also make the transition from interpreting position versus time graphs to interpreting velocity versus time graphs. The third strand, Investigating Newton’s Laws of Motion, provides students the opportunity to wrestle with the concepts in each of the three laws and then apply them to real life situations.

Special Instructions for Interpreting the Curriculum Guide

VOCABULARY The Key Vocabulary lists found in each investigation are color-coded as follows:

GREEN = ESSENTIAL WORDS These are words that are intended to be introduced in this unit and will require multiple exposures for students to develop an understanding of their meaning. They are essential to achieving the learning targets of the investigation and are specific to the topic of the investigation.

RED = IMPORTANT WORDS These are words that students need to make meaning of but they were often exposed to them in prior units or in an earlier grade level as former “Essential Words” and may not need multiple exposures to recall their meaning. It is important to not assume that every student already has an appropriate level of understanding for these words just because they were exposed to them previously. Even for students who seem to know the words a deeper understanding should be developed after completing the investigation at this level.

BLUE = PROCEDURAL or GENERIC SCIENCE WORDS These are words that are not specifically related to the topic of the investigation but they are still important to understand in order to understand either the instructions or explanation related to the investigation. For example, if a student is asked to provide a scientific description of an observed motion it is important that the student know what it means to give a scientific description of motion.

Formative Assessment Tool Included in your grade level materials are note cards as well as red, yellow and green stickered dots. These can be used to give each student his/her own red light/green light card to keep on the desk. This card can be held up by the student upon your request with two of the three dots covered. The dot left uncovered should represent whether the student needs you to stop, slow down/proceed with caution or go on depending on his/her own comfort level with the material at that point.

SEQUENCE OF EXPERIENCES The components within each investigation were developed in specific sequences in an effort to logically develop understanding about each topic. The sequence of events is provided for each investigation as well as recommended groupings and a possible time frame. The time frame can vary quite a bit depending on your specific students and class schedule; however it is important to make an effort to maintain the sequence of events and often the grouping suggestions as well.

TEMPLATES All of the templates and written materials are included in the electronic files on SharePoint.

ASK THE QUESTION Each new investigation should be introduced by asking the investigative question that serves as the title of the investigation. For example, the first investigation is titled “How do scientists describe motion?” Working toward developing a complete answer to that question is the overall goal of the investigation. The final discussion/reflection of an investigation should use the investigative question as its focus. Investigating Motion: Position, Speed and Velocity

Investigation #1 How do scientists describe motion?

A scientific description of motion is one that is accurate, precise and complete. Today’s activity is a game that is used to introduce the topic of force and motion by having students observe and describe motion. Their descriptions are used to recreate the motion and that is when students recognize the need for a more scientific description. The same game is used to begin the Force and Motion unit for all the middle level grades. The game is the same but the level of complexity is increased as the students progress through grades six, seven and eight. The concepts students should have by the eighth grade include: frame of reference, origin, position, direction, speed, constant speed and changing speed. In addition to introducing the topic the game can be used as a pre-assessment to see where students are in their thinking. The topic of force and motion can be a challenge for many students and that is why the opening activity was chosen as one that is fun but also sets up the idea of the need for better descriptions of motion.

Learning Target(s):

 I can use words to scientifically describe motion. This means that I can accurately, precisely and completely describe motion in words.

Key Vocabulary:

Motion, scientific description, frame of reference, origin, position, direction, time, speed

Sequence of Experiences: 1. Ask the Question- Intro. To Investigation  1-2 minutes 2. Lesson Preparation in Notebooks  5 minutes 3. Observe and Describe Motion  2-3 minutes 4. Reach Consensus  5 minutes 5. Match Motion/Discussion 1  5-10 minutes 6. Observe, Describe and Reach Consensus on Motion II  3-5 minutes 7. Motion Match II and Discussion II  5 minutes 8. Repeat steps 6 and 7 for Motion Match II and IV  15-20 minutes

9. Reflection  10 minutes

Materials:

Provided in grade level kit:  Template of “Motion Matching Record Sheet

 Dry erase boards

To be provided by the teacher/student:  Copies of the “Motion Matching Record Sheet” - one per student

 Dry erase marker and eraser

 Science notebook

Lesson Preparation:

Have students begin each new investigation by preparing their notebooks. The preparation includes: unit title, date, the investigative question and their Progress Chart. The learning targets and preview section of their Progress Chart should be completed at this time. (See below)

Learning Target(s) Preview Main Ideas Monitor Have students write Students judge how This area is for Students judge how down their learning well they think they reflective notes on well they think they targets in this know each target by each target. know each target by column choosing one of the choosing one of the progress symbols progress symbols listed below the listed below the chart chart and writing that and writing that symbol in the column symbol in the column across from the across from the target it is target it is previewing. monitoring..

Progress symbols:

= I can do that ? = I have a question or I can’t do that  = I could do that if I review it

Activity: Motion Matching Game

As noted, the essence of the motion-matching activity is the translation of an observed motion into verbal/written descriptions, followed by the translation of the descriptions back into reenacted motions. For this game to run smoothly, a practice round must be conducted. The teacher should prime a student volunteer in order to take full advantage of the game’s instructional potential. The teacher and student agree beforehand on the first motion to be enacted, i.e., walking at a steady speed. This demonstration serves both to show what the activity is about and at the same time start generating motion concepts. (This activity is adapted from an article in The Physics Teacher, Vol 47, October 2009)

Practice Game One:

 The teacher outlines the nature of the game to the class, asks for a volunteer (the student in-the- know), and then leaves the room.

 The student volunteer then enacts a basic first motion by walking at a slow steady pace in the front of the room while the other students observe. (Optional Suggestion: Use a video camera to capture the motion and replay it for students if they need to have the motion repeated while recording their observations. You can even slow it down during discussion time to help students see what everyone is talking about.)

 The teacher is then called back in and students individually write down observations on their “Motion Matching Record Sheet” for the motion that they observed—allow about 1 minute for this.

 In small groups have students share observations and come up with a list of instructions on how to reproduce the motion observed. Each student records those steps on his/her own record sheet and the group recorder writes them on a dry erase board to hold up for the teacher to see.

 The teacher now has some control of how the game goes by selecting from the descriptions offered and deciding which to act on first, ready to take advantage of inadequacies in the descriptions by deliberately enacting “wrong” motions allowed by the description.

 Below is an illustration of the kind of sequence and dialogue one hopes for in students’ first encounter with this activity. o The teacher, pointing to a selected student, asks the person to call out the instruction. o –“Walk slowly!” [speed] o Teacher walks slowly but starts from the “wrong” place in the room. Stumbles into a bench/desk. o –“No, you’re starting from the wrong place! Start at the end of the board!” [initial position] o Goes to the board but to the wrong end, and starts walking from there. o –“That’s the wrong end! Start from the other end of the board!” [frame of reference; initial position] o Goes to the correct end but then climbs up onto a conveniently placed stool. Steps off it with interesting results o –“No, not from up there. Start on the ground!” [frame of reference; three-dimensional] o Starts at the correct spot but then walks out into the room, i.e., in the wrong direction. Thus bumps into a person. o –“That’s the wrong direction – go parallel to the board!” [initial direction] o Stands at the correct spot, facing along the board ready to walk, hesitates...and then walks backward. o “Silly, not backward! Walk forward this time!” [initial direction; reference axis] o Starts by walking forward but thereafter takes a wandering path. o “No, not curvy ... walk in a straight line all the time.” [straight-line motion] o Walks in a straight line in the correct direction... but speeds up along the way. – “No, don’t speed up – walk at a steady speed all the time.” [constant speed] o Walks at constant speed—but much too slowly. o –“You’re going too slowly ... move faster.” [speed magnitude; qualitative] o Walks again but much too fast this time. – “Not so fast! You’ve overdone it. Move at...um... medium walking pace.” [speed magnitude, refined] o The teacher moves “correctly,” fully constrained now. o –“That’s it ... finally!” [accumulated descriptors all in play]

The teacher chooses actions that are in accordance with students’ descriptions which show and emphasize incompleteness or inaccuracies of descriptions. For example, most students will probably say “move in front of the blackboard”. The teacher can start from an obviously wrong point and move in a wrong direction across the room or backwards. Also the teacher can move in a wavy path. The importance of specifying straight line motion, choosing an origin and direction for one dimensional motion as well as specifying an initial point can be made clear. Specifying constant speed can also be brought out. Note that the students use their own observations and words to describe motion and can directly experience the inadequacies of their descriptions, which can lead to improvement. Note that we need to choose an origin and directions; here only one direction is needed. Next the idea of the initial point and final point must be developed. The initial point is frequently at the origin, but these two should be distinguished, for example using two different initial points in two different games. Time can be introduced as an important part of describing motion; how long does it take for the person to move from initial point to final point? Is the position changing rapidly or slowly allows the introduction of velocity and speed. As we will learn later, velocity includes direction, while speed does not.

 The criterion for success is that the original motion enactor must agree that the reenacted motion matches the original.

 For each motion act, before going on to the next, it is important to reflect on the concepts that arose and what has been learned and how. The ultimate message is the motion concepts, not the game. Have students record any refinements that should be added to their original observations in the “Class Refinements” column found on their record sheet.

 Next, move on to Motion Match II, with a new student who is not in “the know”. Repeat basic game steps and re-enter the room ready to follow directions in order to replicate the motion. (Alternative: Once students understand the game, the teacher no longer needs to be the re- enactor; this can fall to another student in class.)

 It should be highlighted that in science there is a need to describe things accurately, precisely, and completely. You may want to ask students if there are any other ways to represent motion other than verbally or written---such as graphs or pictures and how these might be helpful in order to guide students towards the next activities.

Reflection:

 Review learning targets and use the “What I Did/What I Learned” summary. This is done by making a T-chart using the input from students. You end up with two columns one for what they did and one for what they learned as a result of having done it. It is important to help students understand the difference between what they did and what they hopefully learned by doing it.

 Have students answer the “Reflection” questions at the bottom of their Motion Matching Record Sheet.

 Students should add notes to the main ideas section in the Progress Chart in their notebooks. Motion Matching Record Sheet Teacher Sample

Individual Observations Group Instructions Class Refinements Motion Match I

Motion Match II

Motion Match III

Motion Match IV

Reflection:

1. What should be included in a scientific description of motion? For 8th grade they should include frame of reference, origin, position, direction, speed, constant speed and changing speed.

2. Compare your observations to the class refinements above to determine three insights you had as a result of this activity.

3. Why is it important to be able to describe motion scientifically? Motion Matching Record Sheet Name ______Date ______

Individual Observations Group Instructions Class Refinements Motion Match I

Motion Match II

Motion Match III Motion Match IV

Reflection:

1. What should be included in a scientific description of motion?

2. Compare your observations to the class refinements above to determine three insights you had as a result of this activity. 3. Why is it important to be able to describe motion scientifically Investigating Motion: Position, Speed and Velocity

Investigation #2 What is the difference between speed and velocity?

Motion in general is in three dimensions: up/down, right/left and forward/backward. Two-dimensional representations of our world are often used as well. A flat map would be an example of that. Although for most of our activities on force and motion we will be concentrating on motion that occurs in a straight line, one-dimensional motion, it is still important that students recognize all three dimensions and how to utilize two-dimensional representations. This is especially true when differentiating between distance and change in position as well as between speed and velocity.

In this investigation students will work through an exercise that will ask them to think in terms of the three- dimensional aspects of an airplane’s motion first and then try to represent that motion in two-dimensions using arrows on a map. This first exercise and the activity that follows it (moving a toy car along a meter stick) are designed to help students distinguish between distance and change in position (Δx) as well as practice representing both speed and direction using arrows. Note the importance of the specification of an origin and accurately locating points relative to the origin. Although sometimes ignored, especially in math class examples of motion, any description of motion is incomplete without an explicit or implicit specification of the position of the origin.

Recognition of the significance of direction in motion descriptions and the need for accurate determinations of change in position allows students to develop an understanding of both speed and velocity. The final activity in this investigation utilizes a constant speed toy car to distinguish between speed and velocity. It also provides students with practice in designing tests and making measurements that lead to the calculation of the speed of the car when traveling in a straight line and when traveling in a circular path.

Learning Targets:

 I can distinguish between distance and change in position.  I can identify change in position as x.  I can distinguish between speed and velocity. (7th grade target)

Key Vocabulary:

speed, velocity, distance, change in position (x) Sequence of Experiences: 1. Ask the Question  1-2 minutes 2. Lesson Preparation in Notebooks  2-3 minutes 3. “NASCAR Racing” Probe  3-5 minutes 4. Exercise 1: Airplane Travel  20-25 minutes 5. Exercise 2: Maneuvering Along Meter Sticks  20-25 minutes 6. Activity: Constant Velocity Car  20-25 minutes 7. Summary: What I did/ What I Learned  5-10 minutes 8. Reflection  2-3 minutes 9. Hinge Question – Strand 1  15-20 minutes

Materials:

Provided in grade level kit:  Template of “NASCAR Racing” Probe

 Template of map handout

 Template of Exercise 2 “Maneuvering Along Meter Sticks”

 Meter sticks – two per group

 Small plastic car

 Masking tape

 Constant velocity cars – 1 per group

 Versa Timers – 1 per group Provided by the teacher/student:  Computer, projector and internet access to show video.

 Post-it notes / slips of paper with tape /document camera

 Copies of any handouts

Lesson Preparation:

Have students begin each new investigation by preparing their notebooks. The preparation includes: unit title, date, the investigative question and their Progress Chart. The learning targets and preview section of their Progress Chart should be completed at this time.

Formative Assessment:

 Administer Probe: “NASCAR Racing” to individuals. Roam around the room as they complete the probe and get a group tally of how many chose each of the answer choices.

 Utilize probe results to inform your approach to the investigation.

 Keep tally for comparison at the end of the investigation.

Exercise 1: Airplane Travel

Part 1:  Tell students to imagine they are going to travel on an airplane. Show the video clip of a flight attendant rapping the flight instructions.

http://vids.myspace.com/index.cfm?fuseaction=vids.individual&videoid=55306122

 Now imagine they are sitting in a plane ready to take off like the people in the video only they are in Lexington headed to Louisville.  Ask them to think about all of the motion the airplane will go through in order to make the trip starting from backing out of the terminal in Lexington to pulling into the terminal in Louisville. Pass out the map handout and allow about 90 seconds for students to jot down their description on the back of their map handout.

 Tell them to turn to their elbow partner and the taller of the two goes first. They get one minute to share their description. Then the shorter of the two partners gets 30 seconds to add anything they have different.

 Randomly pick students to share parts until the class has a complete description.

 Ask “What type of motion did the imaginary airplane have? 1-dimesional, 2- dimensional or 3-dimensional?” Have students record their answers on their dry erase boards and use them to report out their answers. Discuss the answer providing examples from the class description to back it up. Have them record the answer on their map handout as the answer to #1 in Part 1.

Part 2:  Tell students they are traveling on another airplane only now their trip started and ended somewhere else but they are to think about the portion of the journey that starts as they are flying over Lexington going 200 miles per hour and ends as they are flying over Louisville still going 200 miles per hour toward their final destination. Instruct them to draw an arrow on their map that would represent the plane’s motion for this particular portion of the trip.

 Now have them imagine they are traveling on yet another airplane and this time the portion of the plane’s motion they are to represent on their map with an arrow is the portion that starts with them flying over London, KY with a speed of 200 miles per hour and ends again flying over Louisville still going 200 miles per hour on the way to somewhere else.

 Have them answer the questions at the bottom of the map handout regarding Part 2.  Discuss their answers and emphasize that the scaled arrows represent speed and direction and can be used to represent velocity because to fully describe velocity you must include a description of both speed and direction.

Part 3:  For this last trip refer back to Part 1 where they took off in Lexington and landed in Louisville but now the only difference is that after they reach Louisville they turn around and head back to Lexington and end their trip back at the same terminal where they started in Lexington.

 Answer the question for Part 3 on their map handout.

 Discuss their answers and emphasize the difference between change in position and distance traveled.

Exercise 2: Maneuvering Along Meter Sticks

 Have students (groups of about 3) work through the exercise using the handout first. Each group will need 2 meter sticks, a little toy car (like a matchbox car) and of course the handout.

 Roam around and clarify instructions as needed.

 Summarize their results through a whole class discussion. Emphasize the difference between distance traveled and change in position as well the difference between speed and velocity.

 Have students return to the probe “NASCAR Racing” and update their answers given what they have learned so far in Investigation 2. The best answer is the one given by Omar. The key difference is that Omar’s answer includes direction as part of velocity.

Activity: Constant Velocity Car

 Ask students to describe what a constant velocity car should be able to do ?

o Have them turn to a partner and discuss their answers.

o Have partners join another two students and reach consensus on the answer.

o Have groups report out and reach a class consensus on the answer.

 Have students work in groups of about 3 for this activity.

o Students will need a meter stick, access to a timer if requested, masking tape and a constant velocity car. o Ask students to mark an origin for their car’s journey with a piece of masking tape and determine the direction their car will travel and place the meter stick in that direction to represent the x-axis.

 Each group is to work out a scheme for estimating the speed of the car as it moves along beside the meter stick. Monitor as they work.

o Have students write a description, make a sketch of their experimental design and answer the following questions in their notebooks:

o Do you get the impression that the speed is constant? Explain.

o Is the direction constant? Provide evidence to support your answer.

o Is the velocity constant? Explain using evidence to support your answer.

 Summarize their results through a whole class discussion. Reflection:

 Review learning targets and use the “What I Did /What I Learned” summary.

 Have students complete the Progress Chart for Investigation # 2 in their notebooks.

Hinge Question: Strand 1

Being able to correctly answer the question asked at the beginning of Investigation #2 is critical in the development of future concepts so we call it a hinge question. Hinge questions mark a pivotal point in the lesson that should be assessed before attempting to build on it further. The question addressed at this point is “What is the difference between speed and velocity.”

o To assess this question you will have your students do a word sort using the terms speed and velocity as the categories for sorting. Have the students title this in their notebooks as a “Formative Check” .

o The terms are placed in a t-chart and the following terms/expressions will be sorted according to the two categories in the t-chart:

o Direction

o Time

o distance traveled

o change in position o Positive

o Negative

o Have students perform the sort individually in their notebooks first.

o Then use post-it notes with the terms/expressions on them and a t-chart on the board (or use a document camera) to have students share out and reach a class consensus on the results of the sort. It is okay if they do not all agree as long as they can defend their choice of where to place the term in the chart. Some may want to place an expression like “Positive” on both sides of the chart because both speed and velocity can be positive. Others may like the idea of placing it on the line between the two columns, it doesn’t really matter which one they choose as long as their reasoning for doing so is sound.

o Have students revise their own sorts as needed. Exercise 1: Airplane Travel Teacher Sample

Part 1:

1- dimensional, 2-dimensional or 3- dimensional? It was 3-dimensional because it traveled in the forward/backward dimension, the up/down dimension and the left/right dimension.

Part 2:

Does stating that the plane is traveling 200 miles per hour completely describe the motion? Use the terms speed and velocity to explain your answer. No, for example…direction in reference to an origin is important in describing velocity. Also, refer back to the descriptions from Investigation #1 to remind them all the things that are needed to completely describe motion.

What might the parts of the arrow represent about the plane’s motion? The length can represent the speed and the point can show direction.

Part 3: Why is it important to know where the origin of motion is located? Use the terms change of position and distance traveled to explain your answer. Change in position is measured in reference to the origin of motion it indicates how much an object’s position has changed compared to the origin. Distance traveled is not in reference to an origin of motion it is simple a total of all distances traveled from the beginning of the trip to the end. For example, in Part 3 the airplane traveled to Louisville and back so its change in position (from the origin of motion) was 0 but it traveled a total distance of about 200 miles if you estimate the distance between the cities as 100 miles. Exercise 1: Airplane Travel Name ______Date ______

Part 1:

1- dimensional, 2-dimensional or 3 dimensional?

Part 2:

Does stating that the plane is traveling 200 miles per hour completely describe the motion? Use the terms speed and velocity to explain your answer.

What might the parts of the arrow represent about the plane’s motion?

Part 3: Why is it important to know where the origin of motion is located? Use the terms change of position and distance traveled to explain your answer. Exercise 2: Maneuvering the Meter Stick TEACHER SAMPLE

PART 1

DO: Move a small toy car in a straight line across the table in front of you. Now, choose an origin; someone hold a finger there until a meter stick can be placed. Then choose a direction for your x-axis, and place the meter stick along this line with 0 cm at the origin. (This is along the line of motion of the toy car.)

NOTE: The initial point of the car does NOT have to be at the origin and in fact is frequently not. Any point along the line of motion corresponds to positive values of x, increasing as one moves away from the chosen origin.

PART 2

NOTE: Any point along the line starting at the origin and going in the opposite direction corresponds to negative values of x, and we could place another meter stick starting from zero and going that way.

DO: Place a second meter stick (as described above) to represent the negative values of x.

ANSWER:

Are positions corresponding to negative values of x valid as positions of objects? yes

PART 3

ANSWER: As the car moves, is it possible for it to move from negative values of x, through the origin and toward positive values of x? yes

NOTE: We call this moving toward increasing values of x. Similarly any motion from smaller values of x to larger values of x are moving toward increasing values of x; note that the final value of x will be larger than the initial value of x.

DO: Now move the toy car toward decreasing values of x going from positive values, through the origin to negative values.

ANSWER: Is it possible for it to move toward decreasing values of x? yes

Is this object always going toward decreasing values of x? no

PART 4

DO: Start the toy car from an initial point half way along the positive x-axis, +50 cm.

ANSWER: Does an object always have to start motion from the origin ? no

DO: From this initial point move it approximately 25 cm in the positive x direction then move it less than 15 cm in the negative x direction.

ANSWER: Observe and record the final position? Varies, it would be +60 cm if it moved exactly 15 cm in the last step

NOTE: The change in position from the initial point to the final point is called the change in position or ∆x and can be calculated by final position (x) minus initial position (x) or x(final) - x(initial) or ∆x = xf – xi , ∆x can be positive or negative.

ANSWER: What is ∆x for the car in this problem? +15 cm if using +60 cm as above but it will vary for your students

Is it positive or negative? positive

What does the sign tell you? the direction in reference to the origin NOTE: If you wanted to know the total distance or distance the car had traveled, you would need to consider all the motion, both going “forward” and “backward”; the sum of all the distances is called the distance traveled.

ANSWER: For the change from the initial point to the final point what is the distance traveled for your car? Varies, my example would of ending at +60 cm would be 40 cm

NOTE: Distance traveled is always a positive number.

ANSWER: Is ∆x different from the distance traveled in this problem? yes

PART 5

NOTE: The change in position is in general different from distance traveled.

ANSWER: What is the distance traveled if you drive from Lexington to Louisville and back? it would equal the distance to Louisville plus the distance back, the distances would be positive and add up, not cancel out

What is the change in position if you drive from Lexington to Louisville and back? 0

Do: Use a Venn diagram handout to compare and contrast distance traveled and change in position.

PART 6

If xf is greater than xi then xf –xi is positive; this corresponds to motion going along the x axis and going toward increasing values of x.

On the other hand, if xf is less than xi then xf – xi is negative and corresponds to motion along the x axis but toward decreasing values of x. For motion in one dimension the only possible directions are toward increasing values of x or toward decreasing values of x.

So, the sign of v = ∆x/∆t, along with the x axis itself tells us the direction of the velocity. We know that a complete description of velocity always includes specifying a direction.

Speed is determined by the distance traveled, which is always positive, and the time duration required to travel the distance, which is also always positive. An equation for speed is s= d/∆t and sometimes we see this as simply speed = d/t; speed is always positive and does not include direction.

DO: Use a Venn diagram handout to compare and contrast speed and velocity.

Exercise 2: Maneuvering the Meter Stick Name ______Date ______

PART 1

DO: Move a small toy car in a straight line across the table in front of you. Now, choose an origin; someone hold a finger there until a meter stick can be placed. Then choose a direction for your x-axis, and place the meter stick along this line with 0 cm at the origin. (This is along the line of motion of the toy car.)

NOTE: The initial point of the car does NOT have to be at the origin and in fact is frequently not. Any point along the line of motion corresponds to positive values of x, increasing as one moves away from the chosen origin.

PART 2

NOTE: Any point along the line starting at the origin and going in the opposite direction corresponds to negative values of x, and we could place another meter stick starting from zero and going that way.

DO: Place a second meter stick (as described above) to represent the negative values of x.

ANSWER:

Are positions corresponding to negative values of x valid as positions of objects?

PART 3

ANSWER: As the car moves, is it possible for it to move from negative values of x, through the origin and toward positive values of x?

NOTE: We call this moving toward increasing values of x. Similarly any motion from smaller values of x to larger values of x are moving toward increasing values of x; note that the final value of x will be larger than the initial value of x.

DO: Now move the toy car toward decreasing values of x going from positive values, through the origin to negative values.

ANSWER: Is it possible for it to move toward decreasing values of x?

Is this object always going toward decreasing values of x?

PART 4

DO: Start the toy car from an initial point half way along the positive x-axis, +50 cm.

ANSWER: Does an object always have to start motion from the origin ?

DO: From this initial point move it approximately 25 cm in the positive x direction then move it less than 15 cm in the negative x direction.

ANSWER: Observe and record the final position?

NOTE: The change in position from the initial point to the final point is called the change in position or ∆x and can be calculated by final position (x) minus initial position (x) or x(final) - x(initial) or ∆x = xf – xi , ∆x can be positive or negative.

ANSWER: What is ∆x for the car in this problem?

Is it positive or negative?

What does the sign tell you?

NOTE: If you wanted to know the total distance or distance the car had traveled, you would need to consider all the motion, both going “forward” and “backward”; the sum of all the distances is called the distance traveled.

ANSWER: For the change from the initial point to the final point what is the distance traveled for your car?

NOTE: Distance traveled is always a positive number.

ANSWER: Is ∆x different from the distance traveled in this problem?

PART 5

NOTE: The change in position is in general different from distance traveled.

ANSWER: What is the distance traveled if you drive from Lexington to Louisville and back?

What is the change in position if you drive from Lexington to Louisville and back?

Do: Use a Venn diagram handout to compare and contrast distance traveled and change in position.

PART 6

If xf is greater than xi then xf –xi is positive; this corresponds to motion going along the x axis and going toward increasing values of x.

On the other hand, if xf is less than xi then xf – xi is negative and corresponds to motion along the x axis but toward decreasing values of x. For motion in one dimension the only possible directions are toward increasing values of x or toward decreasing values of x.

So, the sign of v = ∆x/∆t, along with the x axis itself tells us the direction of the velocity. We know that a complete description of velocity always includes specifying a direction.

Speed is determined by the distance traveled, which is always positive, and the time duration required to travel the distance, which is also always positive. An equation for speed is s= d/∆t and sometimes we see this as simply speed = d/t; speed is always positive and does not include direction.

DO: Use a Venn diagram handout to compare and contrast speed and velocity.

Investigating Motion: Changes in Motion

Investigation #3 What does constant velocity look like?

Students will utilize the Motion Detector and LabQuest system (MDLQ) to explore a variety of motions that are all examples of motion with a constant velocity. They will analyze position versus time graphs created by the MDLQ for each of the various motions and learn to describe the motion by interpreting the graphs and using them to calculate velocity. They will also compare the position versus time graphs to velocity versus time graphs for these motions and introduce the term acceleration.

Learning Targets:

 I can scientifically describe motion with a constant velocity in words and with graphs.  I can describe the motion of an object represented by a velocity versus time graph.  I can distinguish between and describe the relationship between a position versus time graph and a velocity versus time graph.

Key Vocabulary:

Constant velocity, position graph, velocity graph

Sequence of Experiences:  1. Ask the Question 1-2 minutes  2. Lesson Preparation in Notebooks 2-3 minutes  3. Pre-assessment Graph 5-10 minutes  4. Exercise 1 with learning check 30-40 minutes  5. Activity 1 1-2 class periods  6. Summary 10-15 minutes  7. Yes/No, Explain Constant Velocity Graphs 5-10 minutes  8. Reflection 10-15 minutes Materials:

Provided in grade level kit:

 Dry erase boards

 Masking tape

Provided in the school kit:

 LabQuest – 1 per group

 Motion Detector – 1 per group

 Motion detector clamp

 Calculator

 Mini dynamics cart

Provided by the teacher/student:

 Dry erase markers

 Removable stickers such as post-it notes or tape and note card

 Copies of handouts

Lesson Preparation:

Pre - Assessment: Graph

 Start Investigation 3 by showing students the following sketch of a graph and asking them “What does this graph tell us about the motion it represents?”  Have students do a Think-Pair-Share to process the question.

 Look for possible misconceptions while they are sharing.

 Be sure to emphasize the importance of labeling because there are many different types of graphs and you cannot describe anything about them unless you know what they represent.

Exercise 1: Preparing the Equipment

Utilize the instructions on the separate handout for students. Monitor their progress and stop groups at the end of Exercise 1 for a learning check before they can continue on to Activity 1. This learning check is really a check for effective use of the MDLQ. Make sure they are able to get acceptable results in Exercise 1 before going on. Students will be using the MDLQ equipment several times within the unit so spending time to be sure they understand how to correctly use the equipment now will save time and frustration later.

Activity1: Comparing Position and Velocity Graphs

Utilize the instructions on the separate handout for students. The comparison of similarities and differences at the end of the activity should be done as a T-chart in their notebooks. Summarize the results with the whole class. Be sure to include sketches of graph shapes as you summarize.

Formative Assessment: Yes/No, Explain Constant Velocity Graphs

Have students complete the handout individually first then collect them and determine whether more time is needed for additional experience and explanation before going on to Investigation #3. Choose a few anonymous examples from the work collected to go over the assessment with the class the next day. Be sure to include examples of good and bad work.

Reflection:

 Review learning targets and use the “What I Did/What I Learned” summary.

 Have students complete the progress chart for Investigation #3 in their notebooks.

 Remind students to include essential vocabulary in their personal glossary.

Investigation 3 Name______Date ______

How to Prepare the Equipment for Using the LabQuest for Detecting Motion

A. Obtain a LabQuest (LQ) and a Motion Detector (MD) from an instructor.

B. Connect the MD to a Digital input connection on the side and turn the device on. The MD starts operating (and clicking) since the MD was connected (and hence activated) when you turned it on.

C. Along the top of the LQ there are symbols or tabs, the first of which (on the left) shows a meter and the second of which shows a graph. When using probes like the MD, these buttons choose the manner in which measurements are displayed - as a meter or as a graph.

D. Most likely the unit started in the Meter mode; if not choose the Meter tab at the top. Aim the MD at a wall or the ceiling and observe the position readings on the meter as you move the MD or move yourself a little and confirm that the values make sense. [The MD sends out a sound signal which bounces off an object and returns; the MD measures the time required for the sound to return and from this measurement an internal computer calculates the distance to the reflecting object.] The MD measures the distance to a reflecting object, so make sure that it is aimed at what you want!

E. Now we are ready for graphs. Choose the Graphs Tab at the top. When the device initializes with a MD connected, the graph mode shows a pair of graphs, a position versus time graph on the top and velocity versus time on the bottom. Today we will be using both of these. The units and limits for the axes when most units initialize are: position in meters varying between 0 and 2.0 m, time in seconds between 0 and 5 seconds, and velocity in meters/second varying between – 5m/s and +5 m/s and time between 0 and 5 seconds.

F. We would like to retain the units and limits for position but change the limits for velocity for our initial work, so we need to turn off Autoscale and reset the units for the second graph y i.e. velocity axis.

G. The LQ default setting of the scale limits is Autoscale. In Autoscale the LQ chooses a vertical scale for the graph which fully shows the variation of the measured quantity. If there is no actual variation in a variable and Autoscale is chosen, the LQ will try to fill the graph with ultra-small variations which tends to obscure the data of interest.

 To turn off Autoscale do the following:

o with a graph showing, choose the Graph pull down menu, then choose Graph Options .

o Along the top of this screen choose Manual rather than one of the Autoscal e options.

o To change the limits on the velocity graph, scroll down on this screen so that you can work on Graph 2 Y Axis. The Top and Bottom refer to the limits of the Y axis graphs. I suggest setting these to +1 and -1 respectively.

o To enter range limits, in Graph Options tap in each field and use the keyboard to enter numeric values. Dismiss the keyboard by tapping the keyboard icon along the bottom of the screen. Click OK to save your changes and return the graph.

 Note that from this menu you have complete control over how the data are graphed. At the end of this section all of the Graphs Menu section of the LQ Users Manual has been pasted. Anytime the data you have taken seem “weird” you may want to examine the scales that either you or the LQ have chosen.

H. Find an open area at least 4 m long in front of a wall. You will be measuring distances using the MD which you can place on a table and move in front of it. If you are moving in front of the MD make sure that it is aimed at waist level so that it does not “see” your moving arms or moving legs. If this does not work, carrying sound reflectors like pieces of cardboard can also help remove extraneous motions and make a better measurement. The spikes in position measurements that come from arm movements, poor reflection or other unintended conditions will cause very spikey velocity measurements. So, it is crucial to make sure that your measurements do not include these spurious “spikey” measurements. Keep trying until you get a spike free measurement.  Once you feel you have a good sample graph completed have your teacher check it to be sure you are ready to begin Activity 1.

Investigation 3 Name______Date ______

Activity 1: Comparing Position and Velocity Graphs

A. Make position and velocity graphs of your motion when you walk away at a constant speed.  To do this start moving, then start data collection by pushing the start button in the center of the LQ (just above the circle of buttons).  If you get a spike, the LQ may Autoscale and carry it into the next measurement; so check the limits before each measurement. It may take several attempts to get good graphs.

B. Look at one of your position versus time graphs. The points are connected; note that the LQ by default connects points, i.e. draws a straight line from point to point. This can be turned off in Graph Options; do this (for all graphs) so that you can see the plotted data more clearly.  Record in your notebook a sketch of position and velocity graphs for moving away - for your best data, including axes labels and units and title the graph according to the type of motion.

C. Repeat steps A & B for: 1. moving away slower but constant 2. faster but constant 3. standing still

D. Note and record the similarities between and differences among the position versus time graphs and the velocity versus time graphs utilizing a T-chart that will be described by your teacher.

SIMILARITIES DIFFERENCES Constant Velocity Graphs TEACHER SAMPLE

Yes/No, Explain

Answer the following question for all of the graphs sketched below; “Does this graph represent constant velocity?” then explain your reasoning for your answer choice.

1) Yes or No? _____NO ______, Explain Position

The upward slant of the line indicates that the position of the moving object is changing as the time changes. This does not mean that it’s speed is increasing so watch carefully what students put in their explanations. Time

YES 2) Yes or No? ______, Explain

Position The position of the object remains the same as time increases. The position remains the same as the time increases. This means the object’s motion is not changing, it is constant. Students may say it is not moving but that is still considered constant motion because it is not changing. Time

NO 3) Yes or No? ______, Explain Velocity

The velocity is increasing as time increases so the motion is not constant, it is speeding up.

Time YES 4) Yes or No? ______, Explain Velocity

The velocity is constant as time increases so the motion is constant, It is moving with a constant velocity so it is not speeding up or slowing down.

Constant Velocity Graphs Name ______

Yes/No, Explain Date ______

Answer the following question for all of the graphs sketched below; “Does this graph represent constant velocity?” then explain your reasoning for your answer choice.

5) Yes or No? ______, Explain Position Time

6) Yes or No? ______, Explain

Position

7) Yes or No? ______, Explain Velocity Time

8) Yes or No? ______, Explain Velocity

Time Investigating Motion: Changes in Motion

How does motion with changing velocity look Investigation #4 compared to motion with constant velocity?

Students will utilize the Motion Detector and LabQuest system (MDLQ) and the motion of their own bodies to explore motions that involve various examples of changing velocity. They will describe these motions in word, graphs and using mathematics in an effort to distinguish between constant velocity motions (such as those in Investigation 3) and accelerating motion.

Learning Targets:

 I can scientifically describe motion with changing velocity in words, with graphs and mathematically.  I can distinguish between constant velocity and acceleration.

Key Vocabulary:

Changing velocity, final velocity, initial velocity, Δv, uniform motion, non-uniform motion, acceleration

Sequence of Experiences:  1.Ask the Question 1-2 minutes  2. Lesson Preparation in Notebooks 2-3 minutes  3. Pre-assessment Probe “Roller Coaster Ride” 10-15 minutes  4. Exercise 1 and Activity 1 20-25 minutes  5.Vocabulary Activity1 15-20 minutes  6. Exercise 2 and Activity 2 40-45 minutes  7.Vocabulary Activity2 15-20 minutes  8. Reflection 10-15minutes

Materials:

 Calculator

Lesson Preparation:

Pre - Assessment: “Roller Coaster Ride” Probe

 Prior to administering the probe you might want to add the three additional choices that were included with the teachers. The additional choices are:

o When you are being pulled up the first hill.

o When you are going fast and speed up even more.

o When you slow down to stop.

 Administer the probe from your Uncovering Student Ideas in Physical Science probes book to individuals and then have them use dots to mark their answers anonymously on large poster sheets located around the room. Make one poster for each example on the probe.

 Discuss group results as far as how many chose each one but do not give away the answer(s) yet.. Exercise 1 and Activity1:

Have students work through the handouts as you monitor their progress. Summarize the results with them and discuss the background section at the end of Activity 1.

Have students get out their “Roller Coaster” probe and make any changes they want to “correct” given the information they now have about the topic. Go over the answers with the class after they have had a chance to self assess and allow them to make more corrections as you go over them.

Vocabulary Activity 1:

Have students do the “Deep Processing Vocabulary” activity in their notebooks using the word “acceleration” as their vocabulary term. A description of the activity is found on page 90 in Tools for Promoting Active, In-Depth Learning (Silver, Strong and Perini) and the reproducible template is found on page 91. If you do not have access to that resource a brief description of the activity follows:

 Have students draw a large box that fills their paper then divide that into four equal boxes.

 Across the center at the top, bottom or center of the page the term “acceleration” should be written.

 In the top left box they are to make a physical symbol with their body that explains what it means to them

 In the top right box they are to write some feelings they have about the term. Use colors to describe their feelings.

 In the bottom left box they are to write what the term means to them in their own words.

 In the bottom right box they are to create a picture in their mind and then on paper to represent the term.

 Have students compare with a partner and then report out as a class.

Exercise 2 and Activity 2:

Have students work through the handouts as you monitor their progress. Summarize the results with them and discuss the background section at the end of Activity 2.

Vocabulary Activity 2:

You might want to model how to do the “Vocabulary Concept Map” activity by using the term “acceleration” as an example. It will also give them some review of that term before trying it on their own with the next term. Use the term “changing velocity” as the vocabulary term for this activity. After they have time to complete it alone be sure to share results in some way. For example, you may choose to give the assignment as homework (after modeling how to do it of course)collect them and then pick random anonymous samples to project with the document camera and analyze as a class.

Reflection:  Review learning targets and use the “What I Did/What I Learned” summary.

 Remind students to include the essential vocabulary in their personal glossaries.

Investigation 4 Name ______Date ______Exercise 1

A. Instrument Set-up

 Obtain a LabQuest (LQ) and a Motion Detector (MD) from an instructor.

 Connect the MD to a Digital input connection on the side and turn the device on. The MD starts operating (and clicking) when you turn it on.

Along the top of the LQ there are symbols or tabs, the first of which (on the left) shows a meter and the second of which shows a graph.

 Most likely the unit started in the Meter mode; if not choose the Meter tab at the top.

 Observe the position readings on the meter as you move the MD a little and confirm that the values make sense.

B. Preparing Graphs for Data Collection

 Choose the Graphs Tab at the top.

The graph mode shows a pair of graphs, position versus time on the top and velocity versus time on the bottom. Today we will be using both of these.

When most MDLQ systems are turned on the position versus time graph will show the unit for position as meters (m) and a limit varying between 0 m and 2.0 meters.

 Keep the default settings noted above for the position graphs produced during this activity.

For the velocity graphs, most MDLQ systems will default to having velocity in meters/second (m/s) with a limit ranging from -5 m/s t0 +5 m/s.

 Keep the unit for velocity as m/s but change the limit to +1 for the “Top” limit and -1 for the “Bottom” limit. To make these changes refer to the instruction sheet for turning off Autoscale and manually setting your units and limits.  Find an open area at least 4 m long with a wall at one end and the motion detector sitting on a table at the other end.

If you are moving in front of the MD make sure that it is aimed at waist level so that it does not “see” your moving arms or moving legs. If this does not work, carrying sound reflectors like pieces of cardboard can also help remove extraneous motions and make a better measurement. The spikes in position measurements that come from arm movements, poor reflection or other unintended conditions will cause very spikey velocity measurements. So, it is crucial to make sure that your measurements do not include these spurious “spikey” measurements. Keep trying until you get a spike free measurement.

Activity 1:

C. Make position and velocity graphs of your motion when you walk away speeding up all the time.

 Instead of moving at constant speed as you did before, start from rest and go faster and faster. If you get a spike the LQ may Autoscale and carry it into the next measurement; so check the limits before each measurement. It may take several attempts to get good graphs. You may have to use “strike through” unimportant data as you did before.

 Remove the lines leaving just the data points. This can be turned off in Graph Options; do this for all graphs (position versus time and velocity versus time) so that you can see the plotted data more clearly.

 Prepare a properly labeled section in your notebook to sketch your best position versus time graph and your best velocity versus time graph.

D. Make position and velocity graphs of your motion when you slow down as you walk away from the MD.

 Repeat the overall procedure you used above in Part C for moving away, but you should slow down as you move away this time. Start out fast and then slow consistently to a stop. You will probably need to “strike through” the initial data that shows you speeding up to go fast prior to the actual slowing down motion that we want to focus on for this graph.

E. Earlier we did experiments with constant velocity (of course showing continuously changing position.) The velocity graphs for these stayed constant with time as illustrated by the horizontal line depicted in the graph.

Answer the following in your notebook. In the velocity versus time graphs you just prepared:

 What shape should they have if the velocity is constant as time progresses?

 What shape did you get?

 Is the velocity constant as time progresses in your graphs?

 Do your graphs represent constant velocity or changing velocity? Background Information

Earlier we investigated changing position in terms of ∆x and represented the rate the position changes over time on a position versus time graph. When the position versus time graph data form a straight line it indicates that the velocity of the object represented by that line is constant. You can pick any two points along that line to calculate the velocity and know that it is the same along the entire line. The formula we used to determine the velocity from two points along the line was…

v= xf –xi/tf –ti or v = Δx/Δt

We can now similarly investigate the rate that velocity changes over time by using a velocity versus time graph. To calculated the rate the velocity changes we use Δv and Δt instead of using the Δx and Δt that are used with the calculations form a position versus time graph. The expression now becomes…

Rate Velocity Changes = vf –vi/tf –ti or Δv/Δt

If a velocity versus time graph forms a straight line that means that the velocity represented by that graph is changing at a constant rate. For example, if it is determined that the velocity changes by 5m/s during the first two data points on the graph and the graph is a straight line then the velocity will also change by 5m/s between the last two data points on that graph. Note that it is the rate the velocity changes that is constant (the same) not the velocity itself. The velocity is always changing but it is changing the same amount during each unit of time that is on the graph. We can say that it is consistently changing.

The graph below is an example of this kind of graph. y t i c o l e v

The graph represents a consistently changing velocity, for the same ∆t we always get the same ∆v. This means that for a straight line v versus t plot, ∆v is proportional to ∆t and that ∆v/∆t is constant. [This is just like for a straight line x versus t plot, ∆x/∆t is constant and for points on the plot ∆x is proportional to ∆t.] Only for straight line plots are the changes in vertical and horizontal quantities proportional to one another like this. Investigation 4 Name ______Date ______

Exercise 2

Describe the motion (as completely as you can) of the objects represented by the velocity versus time graphs in the following sketches.

A. Velocity (m/s)

Time (s) B. Velocity (m/s)

Time (s)

C. Velocity (m/s)

Time (s)

D. Velocity (m/s)

Time (s)

Activity 2: E. Use your own motion in front of a MDLQ to match the

velocity graphs you described in Exercise 2.

 Each person should do several of these.

 Remember to make sure the scales on the velocity axis are reasonable. .  Record several graphs and associated motion descriptions in your notebook.

Background Information:

Non-uniform motion of an object is always associated with a net force on the object; there is a net force when the forces on the object do not balance out. [If all the forces on object are balanced we call that balanced forces for which there is no net force, since all the forces balance. For balanced forces or no net force we observe uniform motion. There will be more on forces and motions soon.

We have been studying two types of motion, uniform motion and non uniform motion.  Uniform motion is constant velocity motion - motion in a straight line with constant speed. Uniform motion includes constant zero velocity, i.e. zero speed, sitting still. ∆v = 0  Non uniform motion includes all other types of motion, all of which involve changing motion, like speeding up, slowing down and changing direction. ∆v is not zero or ∆v ≠ 0 Investigation 4 Name ______Date ______

Vocabulary Concept Map CATEGORY

COMPARATIVE CONCEPTS

Changing Velocity

EXAMPLES

DEFINITION / DESCRIPTION

Include all of the following in your definition: Changing velocity, final velocity, initial velocity, Δv Investigating Motion: Changes in Motion

What Happens When a Constant Net Force is Investigation #5 Applied to an Object?

Students will utilize the Motion Detector and LabQuest system (MDLQ) along with a fan cart to explore what happens when a constant net force is applied to an object. The concept of proportion will begin to be explored and developed as t relates to force and motion. This will help prepare students for a deeper understanding of the relationships involved in Newton’s Laws that will be studied at the end of the unit.

Learning Targets:  I can collect and use data to show what happens when a constant net force is applied to an object.  I can use proportional relationships to make predictions about force and motion.

Key Vocabulary: Force, balanced force, unbalanced force, net force, constant net force, proportional

Sequence of Experiences:

Pre-assessment Probe ““Force and Motion  Ideas” 10 minutes  Ask the Question 1-2 minutes  Lesson Preparation in Notebooks 2-3 minutes  Exercise 1 10-15 minutes  Exercise 2 25-30 minutes  Vocabulary Activity 1 10-15 minutes  Activity 1 40-45 minutes  Activity 2 25-30 minutes  Exercise 3 25-30 minutes  Vocabulary Activity 2 10-15 minutes  Reflection 10-15 minutes Materials:

 Probes Book

 Heavy duty aluminum foil

 Masking tape

 Fan carts

 AAA batteries for fan carts

Pre - Assessment: “Force and Motion Ideas” Probe

 Administer the probe ( page 79 in the probes book) to individuals and then have them use dots to mark their confidence level in their answers using color coded highlighters or stickers. Green = got it, yellow = not sure, red = not a clue

 Collect their results and analyze them for misconceptions that might occur in the remaining investigations. You should plan to use it again at te end of the unit to judge their progress prior to the summative assessment.

Lesson Preparation:

 Have students begin each new investigation by preparing their notebooks. The preparation includes: unit title, date, the investigative question and their Progress Chart. The learning targets and preview section of their Progress Chart should be completed at this time. Exercise 1

This exercise serves as a brief review of concepts addressed in prior grade levels; however it is important to refresh the memory of students on the topic. This can be used formatively for you to judge if they are ready for the rest of the exercises and activities. Have students complete the work alone first and then you can have them consult a friend to compare notes before going over it as a class.

Exercise 2

Have students use the reading strategy “Pairs Read” from page 94 of McRel’s Teaching Reading in Science as they read the background information in Exercise 1. A brief description of the activity follows:

 Have pairs of students take turns reading one paragraph at a time aloud to each other.

 After the reader finishes reading a paragraph the listener summarizes the main ideas and supporting details verbally to the reader. The listener may ask the reader questions in order to clarify things in his summary.

 Students alternate roles as reader and listener until the assigned section is completed. Then they cooperatively summarize the main ideas and discuss supporting details.

 Each student should record the final summary and supporting details in his notebook and pairs should report to the teacher for a learning check prior to going on to Exercise 2.

 The learning check can consist of you questioning the students and/or looking over their summaries.

Vocabulary Activity 1: Comparing Terms

 Utilize the “Comparing Terms” template to address the terms net force and constant net force.

 Students may want to make sketches in place of or in addition to their descriptions. Share results.

Activity 1

 Class discussion of the results after students complete the activity.

Activity 2:

 Students will perform the fan cart activity but with half the force of the original fan after modifying one of the batteries.  Summarize results in class discussion. When you look at #7 you need to take a little time to discuss the proportionality concept and how it relates to force and acceleration in this case. This will lead students into Exercise 3.

Exercise 3

 Begin this exercise as an extension ot the discussion of the last question (#7) in Actvity2. Start by having students brainstorm what they think it means when we say that two quantities are proportional to each other.

 Jot down the class list of brainstormed definitions by having each group contribute what they feel is their best definition. Students will record this liost as their answer to #1 in Exercise 3.

 For the remainder of Exercise 3 you may choose to have students work independently, as a group or work through the exercise together as a class. This would depend on how much help you think they need. Consider their responses to the brainstormed definition when deciding on how to approach it.

Vocabulary Activity 2: Frayer Model

 Utilize the Frayer model template to address the term “proportional”

Reflection:

 Review learning targets and use the “What I Did/What I Learned” summary.

 Have students complete the progress chart for Investigation #5 in their notebooks.

 Remind students to include the essential vocabulary in their personal glossaries. Investigation 5 Name ______Date ______Exercise 1

Using arrows to represent forces

Just like we used arrows for velocity, we will use arrows for force. Both force and velocity need to have direction and size to be fully described. The length of the arrow is scaled to represent the size or strength of the force and the direction of the force is shown by the arrow tip. A short arrow represents a smaller sized force than a larger one.

Figure 1: Representing two forces in the same direction, one larger in strength than the other.

Figure 2: Representing two forces of same strength but acting in different directions

#1) Draw a square object and use force arrows to show a situation where the forces are balanced. #2) Draw a square object and use force arrows to show a situation where forces are unbalanced.

#3) Can we have balanced forces if one force is applied to a body?

#4) Show the forces acting on a small low friction cart when a fan is attached and blowing.

#5) Show the forces acting on a small wooden block laying on a table when a string is attached and the block is pulled at constant velocity. Investigation 5 Name ______Date ______Exercise 2

Background Information

DIRECTIONS: Use the “Pairs Read” strategy to read and summarize the following background information. Have your teacher check your summary before going to Activity 2..

Uniform and Non-uniform Motion

We have learned that it is important to distinguish between uniform motion and non- uniform motion. For example when an object is speeding up or slowing down we have non-uniform motion. Note that when an object is speeding up or slowing down we have a ∆v. So, we can further characterize non-uniform motion as motion with a ∆v. Uniform motion has a zero change in velocity so ∆v = 0 for uniform motion.

 Uniform motion is constant velocity motion. Uniform motion includes: o motion in a straight line with constant speed o constant zero velocity ( zero speed or sitting still) so ∆v = 0.

 Non uniform motion includes all other types of motion, all of which involve: o changing motion (like speeding up, slowing down and changing direction).

o ∆v does not equal zero so ∆v ≠ 0

Net Force and Changing Velocity

Now we can note that when there is a net force we have ∆v. The logic of this is: unbalanced forces → net force → changing motion → ∆v.

Furthermore, the direction of the ∆v is in the same direction as the net force.

net force

Putting It Togethe r So Far

Net force and ∆v go together:  net force causes ∆v

 ∆v causes non-uniform motion

Balanced forces do not result in a net force, with balanced forces:  ∆v = 0

 motion is uniform

Putting It ALL Together

As you have suspected all along, changing motion (speeding up or slowing down) is called accelerated motion. Changing motion is motion with a ∆v, so acceleration is associated with ∆v and in fact acceleration is:

 “a”

 ∆v/∆t

 the rate of change of velocity

Note that acceleration and ∆v are in the same direction. Whenever you want to know the direction of the acceleration, determine the ∆v and you have it.

Now we can see that net force → acceleration, following the logic unbalanced forces → net force → changing motion → ∆v→ a

Net Force and Acceleration Net force not only leads to acceleration, but it is found that the net force and acceleration are proportional to one another. The symbol α indicates a proportionality between two quantities. So, net force α acceleration

For Example:

If we are pushing on a body and increase the net force then we get a larger acceleration. Since net force and acceleration are directly proportional, if we double the net force we double the acceleration. The direct proportional relationship between net force and acceleration can be written in equation form: net force = (constant) acceleration OR net force = (constant)a

This means that if acceleration is multiplied by some constant quantity it is equal to the net force. So in the example above, if the constant is truly constant when net force doubles the acceleration must be doubled or the equality would not hold true.

 Have your teacher check your summary before going starting Activity 1. Investigation 5 Name ______Date ______Vocabulary Activity 1

Comparing Terms

I. Think about how the terms net force and constant net force are alike and how they are different. Brainstorm some of those ways in the T-chart below.

Net Force Constant Net Force

II. This time compare the terms net force and constant net force in terms of the impact they have on the items listed in the left column below. In addition, provide examples that illustrate what you mean.

Impact on: Net Force Constant Net Force Example(s)

MOTION

VELOCITY

ACCELERATION Investigation 5 Name ______Date ______Activity 1

Setting Up

You will be measuring position and velocity like we have done before only this time you will be using a fan cart moving away from the MDLQ.

SAFETY! When you use the fan cart be careful. If the fan is hard and exposed use safety glasses in case the propeller flies apart. Also, people have drawn blood from hard blades hitting fingers so make sure your fingers are not near the blades when you turn on the cart.

1. Examine the fan cart without turning it on. a) Check the wheels rolling across the table for low friction. Comment:

b) Although the fan cart calls for using two AA batteries it will work best for our experiments to use 2 AAA batteries. Open the battery compartment and make sure two AAA batteries are in place.

c) Turn on the fan. Does the fan speed seem to stay constant?

d) Do you find it reasonable that when the fan is attached to the cart and the fan blades are turning at constant speed that a constant force is pushing on the cart?

e) Most people find this reasonable and we are going to assume that is the case. We are going to use the fan to give a constant force on the cart.

2. Predictions first. a. What will be the effect on the motion of the cart of the fan providing a constant force? Explain in words and with a sketch of the forces involved using arrows to represent the forces as in Exercise 1.

b. What do you predict the position versus time graph will be? (sketch it) c. What do you predict the position versus time graph will be? (sketch it )

d. Discuss your predictions within your lab group.

e. Share your predictions with other groups before going on.

3. Obtain a LabQuest (LQ) and a Motion Detector (MD) from an instructor.

a) Connect the MD to a Digital input connection on the side and turn the device on. The MD starts operating (and clicking) since the MD was connected (and hence activated) when you turn the LQ on.

b) Along the top of the LQ there are symbols or tabs, the first of which (on the left) shows a meter, the second of which shows a graph and the third shows a table. When using probes like the MD, these buttons allow you to choose the manner in which measurements are displayed - as a meter or as a graph or a table.

Most likely the unit started in the Meter mode; if not choose the Meter tab at the top. Observe the position readings on the meter as you move the MD a little and confirm that the values make sense.

c) In the meter mode, choose the pull down menu sensors and choose data collection.

d) While taking MD data the LQ takes data in the Time Mode as indicated at the top. I suggest setting the Rate to 50 samples per second and length to 10 s. Choose OK and these selections will be shown along the right side of the meter.

e) Now go to the Graph tab, where there will be an upper and lower graph, showing position and velocity respectively, over a stretch of 10s (as we chose.)

f) Make sure the surface you are going to use is flat.

g) Set up the MD so that the MD is facing along the empty table so there will be room for the cart to move along the table in a direction away from the MD.

h) There are two selections on the inner face of the MD. The selection showing on the right is a ball and a person; choose that one. (After taking some data, you may want to see if the left selection works better for your group.)

i) Along the bottom of the screen are icons, the first of which represents HOME. The next two are calculator and keyboard. Choose HOME

j) Now we are ready for graphs. Choose the Graphs Tab at the top. When the device initializes with a MD connected, the graph mode shows a pair of graphs, position versus time on the top and velocity versus time on the bottom. 4. Today we will be using both of these. After we make our first run we will be able to choose the units we want for the axes for subsequent runs.

5. With a10 second duration for the experiment, there is no rush; we will choose the region of interest after taking the data for each run.

Data Collection

1. Group members need to divide the following tasks up among the team:

a. Start and stop the data collection

b. Turn on the fan and release the cart

c. Observe and watch for anomalies as the cart moves

d. Catch the cart before it runs off a table or crashes

2. Start the data collection, release the cart and allow it to go along the flat surface and catch it. Allow the experiment to go all the way through.

3. Examine the data to see if it is reasonable over some region. Remember we delayed the beginning and kept taking data after the cart had stopped, so we must focus only on the region of interest. We can do this by striking through the data outside our region of interest and striking through these data.

a) There is probably a spike at the end path of the cart in the velocity graph, when the cart was suddenly stopped. We are not interested today in that spike, so using the stylus to touch and leave on the screen starting to the left of the spike and slide it all the way to the end, highlighting that region. Choose graph and then strike through data.

b) Similarly strikethrough data at the beginning of the path of the cart.

4. If you have spikes in your position data, most likely the MD is not aimed well or you got your hand in the sight of the MD or the cart was not released well…

5. Even if you have good data, you need to try to improve your data set by taking another run. In the upper right hand area, on the row below the tabs, there is an icon that is reportedly a file cabinet and a run number is beside it. Use your stylus to push on the file cabinet, which will save run 1, and prepare the unit for run 2 with the current setup.

6. Make another run, and repeat the steps above to choose the region of interest. Repeat, saving each run in the file cabinet, until you have one good set of data.

7. Choose your best set of data and change scales so that you can focus on the shape of the curves. Discuss with your group what the axes scales should be changed to.

I suggest using 0 for the left and bottom choices for the position and time in graph 1 along with your selections for the top and right limits for position versus time and all limits for velocity versus time.

To change the graph scales, choose Graph Options, choose Manual, and then choose the limits for graph 1 and 2; note scroll bars on the right for moving selections up and down.

8. Are the data you observed for position versus time and velocity versus time consistent with your predictions? Explain.

9. Discuss and record possible sources of error.

10. Knowing that acceleration is ∆v/∆t, consider a smoothed v versus t curve and predict whether the acceleration is changing a lot or is fairly constant.

11. After you make your prediction, see what the LQ got for acceleration for your best run by choosing Graph Options, in the white square for graph 1 choose acceleration and uncheck position; now graph 1 shows acceleration.

Since the rate of change of velocity should be constant, the acceleration should be constant. Is the value observed in the graph consistent with your prediction?

12. Consider how net force and acceleration are linked in this experiment. Most people believe that the fan provides a constant force to the cart. Do you agree with this idea? Explain why or why not.

13. Most people observe that when there is a constant force there is a constant acceleration Investigation #5 Name ______Date ______Activity 2

Changing the Fan Speed.

1. If the fan has a lower speed, predict whether the net force on the cart would be higher or lower with the low speed fan.

2. What is your prediction about the acceleration with a lower net force; would it be greater or lesser?

3. Prepare to do the experiment to check out your prediction. To lower the speed of the fan you must do the following:

a) Remove one of the AAA batteries.

b) Take the battery you removed and put a piece of masking tape on each end to cover the electrical contacts.

c) Wrap one layer of heavy duty aluminum foil around the battery and make sure the contact ends are covered with aluminum. By doing this you are allowing the battery to act as a conductor so that the fan circuit is still complete but by taping the contacts first you have eliminated the battery as a power source. Thus you will have essentially cut the power source to the battery in half.

d) Put the covered battery back in the cart and replace the cover.

4. Repeat the procedure that you used in Avtivity 1 but this time you are using the fan cart that is powered by only one battery.

5. Record your results as you did in Activity 1.

6. Was your prediction correct? Explain. Provide evidence from your data to support your explanation.

7. Most people observe that smaller net force results in smaller acceleration and with a number of careful experiments find that the net force and acceleration are proportional. What do you think that means? Investigation 5 Name ______Date ______Exercise 3

Proportions and Predictions

1. As a group, brainstorm what you think it means when two quantities are proportional to each other. Use this list of responses to come up with a definition for the word “proportional.” Be prepared to share that definition with the class. Record your definition and the definitions from the other groups in the space below.

2. Let’s start with two quantities that are pretty familiar to you already, the diameter and the circumference of a circle. When comparing the two you find that for any particular circle if you know one of the quantities you can predict the other one. They are related in a consistent way numerically and that allows you to make predictions.

“d” “c”

a) How are the circumference and the diameter for a circle related?

b) Since these two quantities are consistently related by a specific numerical factor we can say they are proportional to each other. This proportionality can be represented as d  c where the symbol  means “is proportional to” in the expression. The two quantities in the proportion are related by some factor that remains constant for all circles. We call this factor a “constant” and use the letter “k” as its symbol. Using the constant in the expression for the proportionality allows us to represent the relationship in an equation. In this case that might be d=kc.

What numerical value is represented by the “k” in this equation?

c) Knowing the value of ”k” that relates two proportional quantities allows us to make predictions about one of the quantities when the other quantity is unknown by simply solving the equation such as the one for diameter and circumference of a circle. For example, if you have a certain circle with a circumference of 4-cm you can solve the equation d=kc and determine that the diameter of that circle should be _____-cm.

d) You can still make predictions about quantities that are proportional to each other even if you don’t know the value of the constant that relates them to each other. I can look at the equation noted above in terms of “k” and get k=d/c. The expression “d/c” in this equation represents the proportionality between “d” and “c” for circles. We can say that the ratio of “d” to “c” is constant therefore “d” and “c” are proportional to each other. Let’s use that proportionality to make the following predictions:

 If d/c must always equal a constant number then if I double c, what must happen to d to keep d/c constant?

 If I tripled “d” what must happen to “c”?

So when two things are proportional to each other the ratio of the two must remain constant and that allows us to make predictions about the quantities involved.

3. Now we will switch to looking at proportional relationships between quantities related to force and motion. Let’s start by looking back at the situation with the constant velocity car (Tumble Buggy) and the relationships involved there.

a) Recall that the formula v=Δx/Δt describes the mathematical relationship used to find the velocity given the change in position and the time interval (change in time) involved.

b) In the case of the constant velocity car the “v” in the equation is constant. That means velocity is serving as the “k” so then we can say that the change in position is proportional to the change in time. Again this proportion can only hold true when the “v” in v=Δx/Δt is constant.

c) We can now use that proportion to make predictions about the motion of the constant velocity car.

 If the constant velocity car moves in a straight line and has a change in position of 100- cm after 5-s, what is its velocity?

 If the constant velocity car moves in a straight line and has a change in position of 100- cm after 5-s, what should its change in position be if it traveled in a straight line for 10-s?

 In other words, if the change in time is doubled what must be true about the change in position if the velocity is constant? d) For the constant velocity car Δx  _____.

4. Now let’s go back to the fan cart. In Activity 1 the fan cart had about twice as much force causing its motion to change than it did in Activity 2 when you disabled one battery.

a) If all other factors (except the net force created from the battery power) affecting the motion of the fan cart are held constant, what would be true about the acceleration of the fan cart in Activity 1 compared to its acceleration in Activity 2?

b) Express the proportionality represented in the situation above in symbolic form:

c) If you determine acceleration for the fan cart with both batteries to be 10-cm/s/s what should the acceleration be for the fan cart with one functional battery? (assuming all other factors are constant)

d) What other factors might need to be held constant regarding the fan cart in order for net force and acceleration to be proportional? (We will be studying some of those relationships when we study Newton’s Laws of Motion.) Investigation 5 Name ______Date ______Vocabulary Activity 2

Use the Frayer Model below to explore the term “proportional”

Definition (in your own words) Characteristics

Proportional Examples (from your life) Nonexamples (from your life) Investigating Motion: Changes in Motion

Investigation #6 What Happens When an Object Changes Direction?

Students will use a soccer ball and the constant speed car to show what happens when an objet moving at constant speed changes direction.

We must address the question of whether a change in direction is accelerated motion. Stated another way, is a change in direction, even if the speed stays constant, non uniform motion? A change in direction in one dimension, i.e. a reversal of direction, is non-uniform motion; note that there must be a ∆v for this to take place. Many of our experiences with motion involve a change in direction away from a straight line. If a change in direction is a non-uniform motion then an unbalanced or net force is required because we know that net or unbalanced forces cause non-uniform motion. (If only one force is acting on an object, the forces must be unbalanced and there is a net force because there is no other force to counteract or balance with the one force that is applied.

Learning Target(s):

 I can explain why changing direction is another form of acceleration.

Key Vocabulary:

Circular motion

Sequence of Experiences:  Ask the Question 1-2 minutes  Lesson Preparation in Notebooks 2-3 minutes  Activity 1 15-20 minutes  Probe “ Ball on a String” 5-10 minutes  Activity 2 15-20minutes  Vocabulary Activity 15-20 minutes Probe ”Spaceships”  10 minutes  Reflection 10-15 minutes  Hinge Question 10 minutes

Materials:

 Constant velocity car

 Templates

 Soccer balls

 Air pump

 String

 Copies of probes and strategies from templates

Lesson Preparation:

 Have students begin each new investigation by preparing their notebooks. The preparation includes: unit title, date, the investigative question and their Progress Chart. The learning targets and preview section of their Progress Chart should be completed at this time.

Activity 1

Have students work in small groups to perform Activity 1. Be sure to emphasize the relationship between net force and acceleration. Pre - Assessment: “Ball on a String” Probe

 Administer the probe to individuals.

 Use the “Sticky Notes” strategy to share results and talk about them or see suggestions on pages 113-114 in the probes book..

Activity 2:

 Students will tie a string on the constant speed car to make it change directions and take a circular path.

Vocabulary Activity

 Students will use the vocabulary tool found on page 88 of the Tools for Promoting Active, In- depth Learning (Silver, String and Perrini) for the term “circular motion”. Have them work individually. When completed you can have them share out with a partner or you can collect them and choose anonymous random samples to go over with the group. A summary of the tool follows:

o First have students define the term in their own words.

o Then have students either sketch or cut out pictures of 3-4 examples of circular motion in their daily lives.

o Finally, have the students write a sentence that explains why his/her pictures are good examples of circular motion.

Probe “Spaceships” and Summary

 Use the probe discussion to summarize Activity 2. Again, the point to emphasize is that by applying a net force you can force an object’s direction to change and changes the motion from constant speed and direction to just constant speed. Therefore, if the velocity changed the objet accelerated.

Reflection:

 Remind students to include essential vocabulary in their personal glossaries. Hinge Question: Investigating Changes in Motion

 Have students complete the “Formative Check” handout for Strand 2. Investigation 6 Name ______Date ______

Activity 1

In Investigation #6 we are trying to find out what happens when an object changes direction. Let’s begin by looking at what causes a moving object to change direction in the first place. To do this you will be doing an experiment with a play ground ball that is tightly blown up.

1. Roll the ball in a hall, an open space in the classroom or outside on a smooth, flat area and observe the motion.

a) Record your observations below:

b) If you let a ball roll unobstructed over a smooth flat surface, what kind of motion is it – straight line, circular, erratic?

2. Roll the ball again, this time have a group member gently hit or kick the ball as it rolls in front of him/her.

a) Record your observations below:

3. Based on your observations of the ball, write your conclusion regarding what it takes to get a moving object to change direction.

Using a ball is also a good approach for experimenting with looking at several different kinds of accelerated motion caused by a force

1. Change the motion of the ball from resting to moving.

a) Describe how you did this.

b) Did you have to apply a force? 2. Make a rolling ball stop.

a) Describe how you did this.

b) Did you have to apply a force?

3. As the ball is rolling by, give it a push or kick in the direction it is already moving.

a) Record your observations of the balls motion:

b) Describe what happened in terms of the balls velocity before and after the extra push/kick.

4. As the ball is rolling by, give it a small push or kick in the direction opposite to the direction it is already moving.

a) Record your observations of the balls motion:

b) Describe what happened in terms of the balls velocity before and after the extra push/kick.

These are all good examples of a force (of course a single and hence unbalanced force) causing a change in motion. The changes you observed involved making the ball change directions, start moving, stop moving, spped up and slow down. Since starting and stopping the motion are just variations of speeding up and slowing down, we are left with three ways net forces can change the motion of an object: speed up, slow down or change direction.

Most people in the world erroneously believe that force causes motion which is not accurate; we have learned that whenever a net force is applied, the result is changing motion, non-uniform motion, accelerated motion. When an object first starts moving, there must be a change in motion from resting to moving, so there must be a net force applied to make this happen. If the starting applied force is removed after the object is moving, as we know, if there is no friction motion will continue with constant velocity. Investigation 6 Name ______Date ______Activity 2

If an object is going in a circle and moving with constant speed, it might seem that it is uniform motion since the speed is constant. However, we just learned that circular motion is non-uniform motion because the direction is changing and we need a net force to make it happen. Uniform motion is motion in a straight line with constant speed.

1. Attach a string to the front of a constant velocity car (Tumble Buggy) that is long enough to reach from the floor to your hands. Start the car and as the car begins to move away gently tug on the string. Keep tugging on the string as needed to keep the car from moving away. Observe the resulting motion of the car.

a) Record your observations.

b) What kind of motion results from your pulling the string? Straight line? Circular? Erratic?

c) What happens if you let go of the string; what kind of motion does the object have now?

d) Sketch the line of motion of the car when the string is being pulled. Then add a sketch of the line of motion of the car when the string is released. Be sure to indicate the point the string was released. e) Draw a conclusion about whether a force must be applied to an object to make It move in a circle. (Does moving in a circle involve the object changing its direction? Is a force necessary for the object to change direction?)

2. Discuss within your group the fact that the moon goes in a nearly circular orbit around the earth and the earth goes in a nearly circular orbit around the sun.

a) Think about and describe the source of the forces that cause them to move in circles.

b) What would happen if this force were turned off?

3. Also think about an experiment where an object on the end of a string is being whirled about your head with constant speed.

a) Do you need to keep pulling on the string to make it go in a circle?

b) What happens if you let go of the string? Does it continue to move in a circle or does it go off in a straight line?

 If we have circular motion we must have a net force applied to change the direction of the motion.

 If the direction changes we have a change in velocity.

 If we have a changing velocity we have acceleration.

 Circular motion is non-uniform motion.

 If the net force is removed, the object then experiences uniform motion, a = 0, straight line motion with constant speed. Investigation 6 Name ______Date ______Vocabulary Activity

1. Define “circular motion” in your own words:

2. Sketch/select 3-4 pictures that represent examples of “circular motion” that you have witnessed at some point in your life.

3. Write a sentence explaining why your pictures are good examples of circular motion: Investigating Changes in Motion Name ______Date ______

Formative Check

The gas pedal of a car is often referred to as an accelerator. Using a form of the word acceleration in this way can make people believe that there is only one way for an object to accelerate.

1. List the three ways an object can accelerate.

2. Identify the type of acceleration that is demonstrated by pushing on the gas pedal of a car.

3. In addition to using the gas pedal in a particular car, identify two more ways that a car could be made to accelerate. Investigating Motion: Newton’s Laws of Motion

How Does Changing the Mass of an Object Affect its Investigation #7 Acceleration?

During Investigation #5 students used the fan carts to find that when all other variables are held constant, force and acceleration are proportional to each other.. This time it is taken a bit further, they will isolate three factors to look at in terms of the motion of the fan cart (net force, acceleration and mass) and learn to specify the proportionality as either directly proportional or inversely proportional. This time students will attempt to determine the relationship between mass and acceleration when the net force is held constant.

Putting together their results from Investigation #5 and this investigation, hopefully they will be able to conclude that the net force and acceleration are directly proportional when the mass is constant and that the mass and acceleration are inversely proportional when the net force is held constant. At the end of the investigation students will be shown the mathematical relationship of these two proportionalities in the form of an equation and it will be introduced to them as Newton’s Second Law of Motion.

Learning Targets:

 I can describe the relationship between mass and the acceleration of an object subjected to a constant net force.

 I can collect and use data to describe Newton’s 2nd Law of Motion.

Key Vocabulary:

Mass, data, Newton’s 2nd Law of Motion, directly proportional, inversely proportional

Sequence of Experiences:  Four Corners Formative Assessment Activity 15-20 minutes  Ask the Question 1-2 minutes  Lesson Preparation 2-3 minutes  Activity 60 minutes  Vocabulary Exercise 15-20 minutes  Revisit Four Corners Activity 5-10 minutes  Reflection 10-15 minutes

Materials:

Provided in grade level kit:  Probe templates

 Fan carts

 Small mass sets

 Batteries

 Heavy duty aluminum foil

 Masking tape

Provided in the school kit:  Probes book

 MDLQ

 Larger mass sets

Provided by the teacher/student:  Copies of handouts

 4 posters/chart paper and markers

Four Corners Formative Assessment Activity

 Prepare four different posters to post in opposite corners of the room. The four posters should have the following choices, again one for each poster. 1. Acceleration Increases

2. Acceleration Decreases

3. Acceleration Does Not Change

4. Can’t Say/ Need More Information

 Read the questions one at a time and have students move to the corner where the poster matches the answer they feel is correct. Give them a minute to discuss within their group why they think it is correct and then have one person from each group report out. DO NOT make any comments that give away the answer. The

 The “Part 1” questions are designed sequentially to help students uncover their own thinking regarding the information they collected in Investigation #5. Each question gets more specific and helps to rebuild the details for them. This serves as a review for them and allows you to make sure they are still onboard with that information before adding to it in this investigation.

 “Part 2” is used as a way to introduce the question for this investigation and it allows you to uncover what they already believe about the topic.

 Part 1 questions:

1. What happens to the acceleration of an object when the force is increased? (Answer = not enough info. But do not tell them the answer yet.)

2. What happens to the acceleration of an object when the net force is increased? (Answer = not enough info. But do not tell them the answer yet.)

3. What happens to the acceleration of an object when the force is increased and all other factors are held constant? (Answer = acceleration increases. You can go over the answer with them. If a lot of explanation is needed by you at this point you might consider reinforcing Investigation #5 before going on with #7)

 Part 2 Question “How does changing the mass of an object affect its acceleration if all other factors are held constant? Again ask the question and let them move to the corner posters and report out to the class. Do not give them the answer at all just let them know that this is the question they will investigate in Investigation #7.

Lesson Preparation:

Activity:

 In “Part 1” students will be using the fan cart with both batteries providing power. You will need to determine the approximate mass of a fan cart with two batteries prior to class. Each group of students will need enough masses to double and triple the initial mass of the cart. Share with them how much the cart weighs before they begin. “Part 2” is where they triple the mass.

 In “Part 3” the students will be deactivating one battery and repeating the experiment from the first part. You will need to remind them to cover the end terminals of the battery they remove with masking tape and then wrap it in one layer of aluminum foil before returning it to the fan cart. The change in mass is negligible since their data will not be extremely accurate, so they can ignore it.

 You may want to talk with them about the general trend you are looking for and not to expect exact data with perfect results. During the discussion is when you should point out the different kind of proportional relationship between mass and acceleration compared ot the one they studied between net force and acceleration. Net force and acceleration are directly proportional when mass is constant while mass and acceleration are inversely proportional when the net force is constant.

Vocabulary Exercise:

 You will need to provide a resource such as a text or reference book or internet access, something that defines Newton’s Second Law. Have students work alone and then share with a partner. Select a few anonymous examples to share with the class. Revisit Four Corners Activity:

 Go back to the Four Corners Activity but this time use just the one question below. This will help you see if students are catching on to the answer to the investigation question.

o What happens to the acceleration of an object when the mass is increased and all other factors are held constant? (Answer = acceleration decreases.)

Reflection:

 Remind students to include essential vocabulary in their personal glossaries.

Investigation 7 Name ______Date ______Activity

Part One:

1) Think about the experiments with the playground ball being kicked, slowing it down, speeding it up and changing its direction. Suppose we replaced the playground ball with a bowling ball, which, of course, has much more mass than the playground ball.

a) What do you think you would observe in the acceleration or changing motion as a result of this increase in mass if you were able to use the same kick applying the same force? b) What do you think you would observe in the motion of a low friction fan cart if you added a weight with about the same mass as the cart itself?

2) Note that we are doubling the mass compared to the plain cart. You may note that the cart with more mass may be pushing down harder on the table and may have a higher friction force. This would be true for objects with measurable friction, like pushing a desk across the floor. However with low friction devices like our cart, the friction remains essentially zero for all reasonable amounts of added mass. (In reality, the friction is never zero but here it is small enough to not be a factor.)

Prediction:

How would the acceleration of the fan cart change if the mass of the cart doubled but the fan speed and thus the net force stayed the same?

3) Now do the experiment by placing enough weights on the cart to double its mass. You will either have to determine the mass of the empty fan cart yourself or ask your teacher.

a) Make position vs. time and velocity vs. time graphs of the resulting motion. Be sure to focus on the region of interest on your graphs.

b) Get an accurate value for this acceleration. You could also measure v/t = acceleration by using the power of your software. Change the velocity scale if doing so helps (choose the velocity plot, use Examine in pull down menu under Analysis). You want to use a scale that will allow you to most accurately determine a value for how much the speed changes in one second. By determining an experimental value for ∆v/∆t you are determining a numerical value for acceleration.

4) How does the acceleration with twice the mass but same net force compare to the acceleration with the original mass?

5) How do your results compare with your prediction? Part 2:

6) What do you think you would observe if you tripled the mass of the cart by adding even more weights; how would the motion of the cart with the tripled mass compare with that of the empty fan cart? Note that since the fan speed is the same in both cases the net force on the cart is the same in both cases.

Prediction:

7) Now do the experiment by placing enough weights on the cart to triple its original mass.

a. Make position vs. time and velocity vs. time graphs of the resulting motion for the low speed fan. Be sure to focus on the region of interest on your graphs.

b. Get an accurate value for this acceleration.

8) How do the results compare with your prediction?

Part 3: 9) Now predict what will happen if you repeat the mass change experiments with a low speed fan.

Prediction:

10) You have done three different masses (fan cart alone, doubled, and tripled) with the high speed fan; now repeat them with the low speed fan. Remember to disable one of the batteries as you did in Investigation #5 to lower the fan speed.

11) How do the results compare with your prediction?

12) Most people observe that as the mass is increased, for the same net force, the acceleration is less. Conversely as the mass is decreased, for the same net force, the acceleration is greater.

a) Do your observations agree with this? b) Do you believe this?

 Previously you verified the law of proportionality between the applied force and the resulting acceleration, when little friction is present. The acceleration is proportional to the applied force; that is, the acceleration doubles when the applied force doubles. Note we did not change the mass of the cart in these experiments.

 The acceleration also depends upon the mass of the carts, however. When there is twice as much mass or stuff the acceleration is halved when the net force remains the same.

 These two dependencies can be written in an equation or proportionality that looks like this (recall that α is a symbol meaning proportional to)

acceleration α net F/m,

where m is the mass and net F is the net force.

Note for a larger m while keeping the net F constant, the acceleration is less, as we observed. For a larger net force while keeping the mass constant we have an acceleration that is larger. Using appropriate units this proportionality becomes equality.

net F = ma

 Congratulations! Through a study of motion, you have uncovered Newton’s Second Law of Motion, which essentially says that the changing motion, or acceleration, of an object depends directly on the net force applied to it and inversely on how massive the object is. That it took over 2000 years of research and the development of calculus to derive these laws should give you an idea of exactly how difficult these understandings are.

Investigation 7 Name ______Date ______Vocabulary Exercise

Newton’s Second Law of Motion Use all of the terms in your Investigation #7 key Locate a definition for Newton’s Second Law of word list to write your own description of Newton’s Motion from a reference book or internet site and Second Law of Motion. write that definition.

Compare your definition to the one you located from a reference source.

Provide three examples of Newton’s Second Law of Motion using moving objects in your daily life and describe how they serve as examples of the Law.

Investigating Motion: Newton’s Laws of Motion

Investigation #8 What is the Relationship between Mass and Inertia? Inertia refers to the tendency of an object to maintain its current state of motion. Similarly, inertia is the tendency of an object to resist changes in motion. Therefore, an object at rest will remain at rest until put into motion by an applied force. An object in motion will maintain its motion in a straight line at constant speed unless a net force speeds it up, slows it down or changes its direction. (This is called Newton’s First Law of Motion.)

The role of inertia and its relationship to the mass of an object is not a tremendously shocking concept for us. That is why we are choosing to deal with it with a few questions to remind students of some sample situations and a simple activity involving the role of mass in collisions.. We will also use this opportunity to develop some reading skills as they relate to science related topics in the news. The article chosen for students deals with an inertia issue. Students will use the article to practice a reading strategy that helps them consider the validity of the source and the information in the article.

Learning Targets:

 I can explain the relationship between mass and inertia.

Key Vocabulary:

Mass, inertia, Newton’s First Law of Motion

Sequence of Experiences:  Ask the Question 1-2 minutes  Lesson Preparation in Notebooks 2-3 minutes  Crash Dummy Demo 5-10 minutes  Exercise 1 : Intuitive Understanding 5 minutes  Exercise 2: Newspaper Article 25-30 minutes  Mass and Collisions Activity 40-45 minutes  Probe: Riding in the Parade 10-15 minutes  Reflection 10-15 minutes

Materials: Provided in grade level kit:  Bendable man

 Wood blocks

Provided in the school kit  Weights

 Dynamics cart

 Probes book

Provided by the teacher/student:  Copies of handouts

Lesson Preparation:

Demonstration:

 Begin with a whole class demonstration of the role of inertia in motion and the role of mass in inertia. The demonstration will simply be crashing a dynamics cart with a bendable man (in or on it) into a wall of wood blocks.

 Repeat the crash but put as much mass as you can on or in the cart before you begin and try to get the cart to move with the same velocity as it did the first time. Make sure to ask about the difficulty level in pushing the cart to the same velocity as the lighter version of the car.

 The impact on the wall will be the obvious observation to discuss and will reinforce the understanding of the relationship between mass and inertia. Students may also note the reaction of the bendable man during the crashes.

Exercise 1:

 Have students respond to the questions on their handouts. Discuss whole class.

Exercise 2:  Go over the “Key Media Questions” (Their and Davies, 2002) with students and talk about the need for them to develop a healthy skepticism of media. You might want to bring in some of the outlandish claims made in advertisements in magazines as an example of why skepticism is needed. Provide students with the questions they will need to answer prior to having them read the article.

Mass and Collision Activity:

 Go over the “Key Media Questions” (Their and Davies, 2002) with students and talk about the need for them to develop a healthy skepticism of media. You might want to bring in some of the outlandish claims made in advertisements in magazines as an example of why skepticism is needed. Provide students with the questions they will need to answer prior to having them read the article.

Probe: Riding in the Parade (page 99)  See notes and suggestions in the Probes book. You can utilize this as a formative assessment and/or a summary.

Reflection:

 Remind students to include essential vocabulary in their personal glossaries.

Recall that inertia refers to an object’s tendency to resist changes in motion. You will be reading a newspaper article that describes a situation in which inertia plays a big role. When you read the article you will be utilizing “Key Media Literacy Questions” (Their and Daviss, 2002) to critique the article and enhance your ability to view media with a healthy skepticism.

1. Imagine needing to accelerate two vehicles - a small car and a large truck. Imagine that you are not on earth but in outer space and using a small rocket engine; notice no friction to worry about.

a) Choose, using your intuition, which vehicle you think would be easier for you to accelerate, changing the speed continually from at-rest to a speed of 12 mph in a certain amount of time.

b) Try to explain what your intuition is suggesting.

2. Similarly, imagine needing to stop two vehicles - a small car and a large truck – on earth.

a) Choose, using your intuition, which vehicle you think would be easier for you to change the speed continually from a speed of 12mph to at-rest in a certain amount of time.

b) Explain why you believe this.

c) What property of the two bodies is different?

We will rely on our intuitive understanding of mass as some “amount of stuff” that affects how much an object resists changes in its motion. In other words, mass measures inertia, the resistance to changes in motion. We investigated this quantitatively in our experiments with the fan cart when we changed its mass. We found that a = ∆v/∆t = net F/m; the greater the mass the less the acceleration and the less the change in velocity.

1. Familiarize yourself with the “ Key Media Literacy Questions” below and then read the article that follows.

2. As you read keep the questions in mind and highlight or underline sections of the article that help you answer the questions.

3. Record the Following in your notebook along with your answers to the questions:

a) Title

b) Date

c) Source

d) Brief Summary of the article.

4. After you are finished you may work in a group of 2-3 people to go over these questions before I discuss them with you.

Key Media Literacy Questions

1. Who created this message and why are they sending it?

2. What techniques are used to attract my attention?

3. What kinds of words are being used? Is the writer using words to stir emotion?

4. What lifestyles, points of view, and values are represented in the message?

5. How might different people understand this message differently from me?

6. What is implied? (Read between the lines)

7. What is omitted from the message? Median barriers placed on deadly stretch of I-65 OFFICIALS SEEKING A PERMANENT SOLUTION

By ‍Andrew ‍Thomason

Bowling Green Daily News

A deadly year so far on Interstate 65 in Hart County has prompted the installation of temporary concrete barriers and the pursuit of a more permanent remedy.

The newly installed temporary barriers stopped a tractor-trailer from crossing the median into oncoming traffic last week, said Mark Brown, spokesman for the state Department of Highways in Elizabethtown.

“They will be up until there is a more permanent solution,” Brown said.

The temporary barriers’ installation came after the deaths of 11 people in a crash on I-65 in March. A tractor trailer crossed the median at mile maker 63 near Munfordville, plowed through a cable barrier and struck a 15-passenger van carrying a Mennonite family to a wedding. Ten of the 12 passengers in the van were killed. After running over the van, the tractor trailer careened into a rock wall, burning up and killing its driver.

A highway plan recently approved by the General Assembly allows the Department of Highways to pursue putting a concrete barrier between the opposing lanes of I-65 in Hart and LaRue counties. Such a barrier might have stopped the tractor-trailer from crossing the median.

The plan also allows for some widening of I-65 to six lanes in the area.

The expansion of about 15 miles of I-65 approved in the plan, from Exit 43 (onto the Cumberland Parkway) to Exit 58 (Horse Cave), should start next spring, according to Keirsten Jaggers, spokeswoman for the Department of Highways in Bowling Green.

This continues the transition of I-65 to a six-lane interstate, which began in the mid-1980s. Both ends of the interstate in Kentucky, which are more urban than the center, have been expanded. The length of interstate between Louisville and Elizabethtown was the first section to be completed. In 1999, a decade long widening of I-65 between the Tennessee state line and Exit 43 was started. About 50 miles of interstate remain four lanes wide. “It’s taken a while to get it completely three lanes (in both directions) and, right now, it’s the expense,” Jaggers said. “It’s just so costly to widen even a mile.”

The new project will expand the northbound and southbound lanes inward, and a permanent concrete barrier is planned.

“If you’re widening to the middle, if you’re pushing those vehicles closer to each other, you’ve got to create a physical barrier,” said Jeff Moore, chief of the Division of Planning for the Department of Highways in Bowling Green.

The history of fatal wrecks on I-65 in Hart County has earned it the nickname Death Valley.

There have been at least 12 fatalities on that 20-mile stretch of interstate so far this year. From 2004 to 2009, there were 24 deaths on I-65 in Hart.

The entirety of I-65 traveling through Kentucky, about 137 miles, averaged 0.81 deaths per mile between 2004 and 2008, according to figures from the National Highway Traffic Safety Administration. The portion of I-65 in Hart for the same time period averaged 1.1 deaths per mile.

Those figures make I-65 the deadliest highway in the state.

Just last week, an infant died after being thrown from a 2002 Lincoln Navigator when the vehicle smashed into a guardrail three miles north of Munfordville.

Lexington Herald Leader, June 7, 2010

Investigation 8 Name ______Date ______Mass and Collisions Activity

Does inertia affect how strong a wall needs to be to stop something?

Let’s do an experiment that will explore our sense of inertia and to model the collision of vehicles with a median barrier

Obtain the following from your instructor:

1. 4 wheel, low friction cart 2. Bendable man 3. Weights 4. many blocks to construct a wall to stop the cart

Part One:

1. Push the cart toward the wall, release the cart and allow it to move toward and hit the wall. In order to draw comparisons with other groups it is important that you release the vehicle with the same velocity in all cases, try to keep velocity constant. Once you release the cart, since it is low friction, it will move at essentially constant velocity until it hits the wall.

2. Experiment with various thickness block walls until you find one thick enough to stop the cart and not allow the cart to break through.

3. Measure and record the thickness of the wall required to stop the cart in terms of blocks or centimeters.

4. Add a noticeable amount of weight to the cart. Try pushing it to see if it is noticeable.

5. Push the loaded cart and release it with the same velocity that you released the unloaded cart. (Experiment until you can release it with the same velocity.)

a) Is the same force required to get the loaded cart moving the same as that for the unloaded cart? Explain.

Part Two:

1. You will be doubling and then tripling the weight you added to the cart in Part One.. Make sure that when you release the loaded cart it is moving with about the same velocity as with the unloaded cart.

a) In which situation would you expect the inertia to be the greatest? Why? 2. Experiment with various thickness block walls until you find one thick enough to stop the cart (with double the original added weight and again with triple the original added weight) and not allow the cart to break through.

b) Measure and record the thickness of the wall in terms of blocks or centimeters required to stop the cart.

 Double mass:

 Triple mass:

c) Compare the thicknesses of the walls in the two cases.

d) Compare your subjective experience of the push required to get the carts moving at the same speed for the two cases.

e) When is the velocity constant?

f) When is the velocity changing?

g) During what two intervals of time is there resistance to changing the velocity?

h) Which object has the greatest inertia? Summarize the results of this activity (Parts One and Two) in terms of mass, inertia and Newton’s First Law of Motion. Investigating Motion: Newton’s Laws of Motion

Investigation #9 What Happens When Bodies Interact?

We call events or processes like pulling or pushing on an object applying a force to the object. Forces always occur between bodies and always occur in pairs. For example, you are pushing on your group- mate and s/he is pushing on you. We cannot have one force without the other. This law of physics is stated as: In any interaction between bodies, there are pairs of forces, equal and opposite forces, acting on the two bodies interacting. When body A exerts a force on body B, body B exerts an equal and opposite force on body A. The equal and opposite forces of an interaction NEVER act on the same body, because an interaction is between bodies.

This insight is not only a description of interactions but is also Newton’s Third Law of Motion. You may have heard this stated (but less clearly so) as: “To every action there is always an equal and opposite reaction.”

This more familiar description of this law has often been misinterpreted and has led to the misconception that force is a property of an object instead of an interaction between two objects. This investigation is designed to provide students with multiple experiences with observing and describing the interactions between two objects and multiple opportunities to confront the common misconception described above. Stations or centers are utilized in this investigation to be able to quickly provide those multiple exposures.

Learning Targets:

I can scientifically describe the way bodies interact.

Key Vocabulary:

Newton’s Third Law of Motion, interact

Sequence of Experiences:  Ask the Question 1-2 minutes  Lesson Preparation in Notebooks 2-3 minutes  Probe: Equal and Opposite 10-15 minutes Activity 1 (Stations): Interacting with Newton’s  Third Law of Motion 45-50 minutes  Activity 2: Magnets 15-20 minutes  Vocabulary Exercise 15-20 minutes  Probe: Apple on the Ground 10-15 minutes  Reflection 10-15 minutes

Materials:

 Balloons

 Bar magnets ( 2 sizes)

 Exercise bands

 Videos: Third Law Song, Cannon Being Shot (Links provided)

Newtons Third Law Example Cannon.avi

Newtons Third Law Touch This (Low Resolution).avi

 Card Stock for printing signs

 Page protectors for station signs

 Stands for station signs

Provided in the school kit

 Probes book

 Cow magnets

 Spring scales

 Bathroom scales  Weights

 Dynamics carts

 Computer and projector for videos

Lesson Preparation:

 Have students begin each new investigation by preparing their notebooks. The preparation includes: unit title, date, the investigative question and their Progress Chart. The learning targets and preview section of their Progress Chart should be completed at this time

Probe: Equal and Opposite (Page 131)

 Administer the probe to individuals. Have each person post responses using sticky notes. Discuss group results without giving away the answer. Let students work through the concept of the 3rd law in the stations. Come back to the probe in your summary of the stations.

Activity 1

 There will be eight stations so you can have up to eight groups working at the same time.  You should monitor to be sure students are making predictions prior to each station activity and then includes observations, sketches (with force arrows) and explanations in their notebooks.  Sequence of stations does not matter.

Possible Stations: 1. Finger Strength Probe (as written on page 127 in probes book) Provide students with a copy of the probe. They will answer the probe and then try it out for themselves. Make sure the exercise bands at a given station are the same color. Probably blue works best.

2. Spring Scales Partner Pull (Caution students in advance not to pull the scales beyond their elastic limit. A gentle pull will work not a huge jerk. 3. Tow Truck Picture

4. Bathroom Scales

5. Magnets

6. Truck Crash (big truck versus little truck)

7. Cannon Video (Use the file provided in th materials list)

8. Balloon Release (Of course a new balloon wil be needed each time a new set of students arrive because of sanitation issues. However, you can purchase cheap balloon pumps at Wal-Mart if you want to reduce the number of balloons used.)

 Go back and address the “Equal and Opposite” probe again in your discussion of the stations. End with video of 3rd law song (Use the file provided in th materials list).

Activity 2

This activity includes questions that look at the interactions of gravity between objects with very different masses such as the interaction between the earth and a human being. Emphasizing that the forces are equal and opposite but the responses to those forces can be very different.

Vocabulary Exercise

Students will be asked to compare the scientific definition of Newton’s Third Law of Motion with the more common phrse associated with the law.

Probe:

Apple on the Ground (page163) –see notes and suggestions in the Probes book.

Reflection:

 Have students complete the progress chart for Investigation #9 in their notebooks.  Remind students to include essential vocabulary in their personal glossaries. PREDICT: Read the probe titled “Finger Strength Contest” and record your explanation in your notebook as your prediction for this station.

TRY IT OUT: Use the exercise bands to try out the second part of the probe. Tie the two ends of the bands together and partners pull on opposite ends. Record your observations in your notebook.

SKETCH: Make a sketch in your notebook to represent your observations above. Include arrows to represent approximate size and direction of the forces involved in the “Action-Reaction”.

EXPLAIN: Provide an explanation for your observations and compare your results to your prediction. PREDICT: Predict what the readings on the spring scales might be if you and a partner connect the spring scales to each other and only one partner pulls while the other partner just holds the opposite end in place.

TRY IT OUT: Record your observations in your notebook.

EXPLAIN: Provide an explanation for your observations and compare your results to your prediction. PREDICT: Predict what the readings on the spring scales might be if you could measure the force with which the tow truck pulls on a car and the force with which the car being pulled is pulling on the tow truck.

EXPLAIN: Provide an explanation for your observations and compare your results to your prediction. PREDICT: Predict what the readings on the bathroom scales might be if you and a partner face each other and place the bottoms of the bathroom scales together, then one partner pushes as hard as he/she can while the other partner holds his scale in place.

EXPLAIN: Provide an explanation for your observations and compare your results to your prediction. PREDICT: What will happen if you place two magnets together on a table top with like poles touching and then let go.

EXPLAIN: Provide an explanation for your observations and compare your results to your prediction. PREDICT: What happens when a small pick-up truck and a large semi-truck collide? Assume they are heading toward each other with both going the same speed.

TRY IT OUT: You can use two dynamics carts with one of them loaded down with weights and simulate the trucks.

EXPLAIN: Provide an explanation for your observations and compare your results to your prediction. PREDICT: Predict the “Action-Reaction” that takes place when a cannon is fired.

TRY IT OUT: View the brief video clip on the computer and record your observations in your notebook.

EXPLAIN: Provide an explanation for your observations and compare your results to your prediction. PREDICT: Predict the “Action-Reaction” that takes place when a balloon is blown up and the opening is held downward when the balloon is released.

EXPLAIN: Provide an explanation for your observations and compare your results to your prediction. Investigation 9 Name ______Date ______

Activity 2

When two magnets interact, one magnet experiences a force and the other magnet experiences an equal and opposite force.

1. Copy the drawing above in the space below and use arrows to represent the forces on the ends or poles of the magnets. Recall that unlike poles, N-S and S-N, attract while like poles, S-S and N-N, repel or push apart.

2. Using two similar sized and similar strength magnets, try to experience these forces, for example with one magnet in one hand and another in the other hand bring them together. You can feel the forces of attraction and repulsion acting on each magnet.

3. When you are holding the magnets still and experiencing the force, your hand is applying a force to each magnet. Why do they not accelerate?

4. Lay the magnets on the table and push them toward one another but releasing them.

a) If you bring the like poles on the two magnets close together and release one of them, what happens?

b) If you now exchange the two magnets so that you release the one that was earlier held, what happens now? 5. Now get a pair of magnets which have similar strength but are rather different in size. Notice that when you hold the magnets the force on each magnet is the same, since the force is an interaction. Does your experience agree with this or do you believe one magnet feels a stronger force?

If you believe they are different sized forces, try switching hands and feel the force again. Devise some other simple experiences to help you believe that the forces on each are equal.

6. Using the different sized magnets repeat the experiments where one is released, including doing the experiment where the magnet being held and the one that is released are exchanged.

a) If the magnets move, which one seems to have the most motion (really acceleration followed by sliding to a stop.)?

b) If the forces of the magnets on another are equal in magnitude, which do you think would have the greatest acceleration, the magnet with more mass or magnet with less mass.

7. When a small car runs into a large truck, the force of the truck on the car is equal and opposite to the force of the car on the truck. The forces are equal and opposite, but the responses of the two bodies are different because the masses are different.

8. The force of gravity is an interaction between two bodies with mass. Of course, the forces are equal in magnitude and opposite in direction by Newton’s Third Law of Motion. If one object had much more mass than the other and both were free to move, what do you think would happen in terms of the motion (acceleration) of the two bodies?

9. Continuing with the ideas of number 8 above, suppose we have two bodies with masses that are very different, one has a mass that is 1023 larger than the other one or 100000000000000000000000 times more massive than the other. (The mass of the sun is about 1023 times as large as that of a typical human being.) What do you think happens? Investigation 9 Name ______Date ______

Vocabulary Exercise

1. What does the prefix “inter” mean?

2. What does the word ‘interact” mean?

3. Compare the scientific description of Newton’s Third Law in “A” below with the common description found in “B” below. Be sure to use your definition for “interact” to help you make the comparison.

A) Scientific Description In any interaction between bodies, there are pairs of forces, equal and opposite forces, acting on the two bodies interacting. When body A exerts a force on body B, body B exerts an equal and opposite force on body A. The equal and opposite forces of an interaction NEVER act on the same body, because an interaction is between bodies.

B) Common Phrase This insight is not only a description of interactions but is also Newton’s Third Law. You may have heard this stated (but less clearly so) as: “To every action there is always an equal and opposite reaction.” Investigating Motion: Newton’s Laws of Motion

How Do Newton’s Three Laws of Motion Apply to Investigation #9 Real Life?

Students will use an example from everyday life and explain how all three of Newton’s laws apply to that situation. The topic they have to work within is Transportation and Safety. The project will include a group presentation in addition to individual written summaries. A demonstration with a wind-up toy will be used as an example to get them thinking about all three laws in a given situation.

Learning Targets:

I can summarize Newton’s three laws of motion and use them to explain/predict the motion of objects in real-life situations.

Sequence of Experiences:  Ask the Question 1-2 minutes  Lesson Preparation in Notebooks 2-3 minutes  Jumping Bean Demo/Activity 15-20 minutes  Project and Culminating Event 2-3 class periods  Reflection 10-15 minutes

Materials:

 Wind-up jumping bean

 Science notebook Lesson Preparation:

 Have students begin each new investigation by preparing their notebooks. The preparation includes: unit title, date, the investigative question and their Progress Chart. The learning targets and preview section of their Progress Chart should be completed at this time

Jumping Bean Demonstration/Activity

 Demo the Jumping Bean hopping around and ask students to describe the motion utilizing all three of Newton’s laws.  Suggest that they can use a jumping bean themselves but recommend that they each try getting out of their own seats and jump up and down a few times to experience the motion.  Partners work together then reach consensus in small groups. Randomly call on groups to report out and come up with a whole class explanation of the motion.

Project and Culminating Event

Students will work in small groups to investigate a specific vehicle that exists in our daily lives and summarize how all three of Newton’s laws of motion are exemplified in the working of that vehicle. Examples include: helicopter, aircraft carrier, scooter, bicycle, garbage truck, dump truck, row boat…

Individual Student Requirements:  Prepare a written summary with force diagrams that explains how all three laws apply to the vehicle they choose.  Participate in the group presentation.

Group Requirements:  Choose a vehicle  Come up with an explanation that all members agree with that describes how all three laws apply.  Prepare a presentation to explain this to the group in a creative way. Use your choice of appropriate pictures, video, demonstrations, sketches, songs… to present your explanation to the class. All group members must participate and be able to answer questions presented to the group.

Summary and Reflection:

 Remind students to include the essential vocabulary in their personal glossaries.