Forces Affecting Objects

Acknowledgments

The Teaching & Learning Collaborative (TLC) gratefully acknowledges the help and advice of the following individuals in the writing of Science Tasks with Otis & Flask:

• Diane Cantrell, Science Education Consultant • Kathy Colasanti, Director of Curriculum, Buckeye Valley Local Schools • Carol Damian, Science Teacher Leader, Worthington City Schools • Chris Doolittle, Curriculum Coordinator, Westerville City Schools • Cindy Roepke, Curriculum Coordinator, Pickerington Local Schools • Eydie Schilling, Director of Curriculum and Instruction, Granville Exempted Village Schools • Jennifer Ullman, Teacher on Special Assignment, Science, Dublin City Schools • Pat Barron, Founding Director and Project Manager, Teaching & Learning Collaborative • Kelli Shrewsberry, Director, Teaching & Learning Collaborative

The Collaborative also thanks the many teachers and students who participated in field- testing the Centers and provided important feedback.

Finally, thanks to the staff of Attaché and of Baesman Printing, Maureen Looker and Bev May of the TLC staff, and Catherine Behrends for the production of this booklet.

About the Teaching & Learning Collaborative TLC is a non-profit organization whose mission is to improve science and mathematics education. It is a coalition of school districts, organizations, businesses and government agencies with whom we collaborate to design and carry out our work. The TLC works at a variety of levels, from the classroom to the state level, to ensure that all students have access to quality education in science and mathematics.

Currently, our work is focused in three areas: • Professional development in science and mathematics for grades K-12 educators • Special initiatives • Tailored contracted professional services

© Copyright 2008 by the Teaching & Learning Collaborative Science Tasks with Otis & Flask cannot be copied or reproduced by any means without written permission of the Teaching & Learning Collaborative except for pages indicated for student use, which may be reproduced yearly without written permission for educational use in a single classroom in conjunction with any of the activities contained in Science Tasks with Otis & Flask.

Forces Affecting Objects

TEACHER INFORMATION

forces affecting objects Teacher Information Teacher Information

Center Summary

This booklet consists of three centers and their associated readings and assessments.

Center 1 – Ramp Rolling/Gravity & Collision involves observing the effect of the non-contact force of gravity and the contact force of collision on the motion of a toy car when rolled down a ramp.

Center 2 – Get Pushy examines the impact of a push on the toy car as it rolls down the ramp.

Center 3 – Magnetic Fishing explores how magnetism can be both a contact and non- contact force. This Center also includes a Final Assessment that the teacher will use to check students’ understanding from all three centers.

Teacher Directions For Setting Up The Centers

Materials: Center 1 - Ramp Rolling/Gravity & Collision and Center 2 - Get Pushy

The following materials are for one station set up. To accommodate more students, mul- tiple stations can be used.

• Toy car (“Hot Wheels” type) • Long (at least 3’) wood, plastic, or foam board ramp (Note: Instead of using a board, you can prop up one end of a long table to form a ramp. Use a box on the floor to catch the car as it rolls off the table-ramp) • Stopwatch or similar timer (if not available, use a clock with a second hand) • 6 books (each 1” or so thick) to help make a ramp, and later, a barrier • 1 copy per student of the Student Packet • 1 copy of the Answer Key • 1 copy of the Student Task Cards

Setting Up Centers 1 and 2

• Provide materials as listed above • Make 1 copy of the Task Card. Optional: Laminate it and /or glue it to a file folder or other stiff material to make it stand up • Make 1 copy per student of the Student Packet • Make 1 copy each of the Answer Key. Make these accessible to students but hidden from view. Optional: Laminate each answer sheet and glue/place each in a file folder marked “Answer Key”

Materials: Center 3 - Magnetic Fishing

• Small circular magnets with a hole in center • String (for the fishing-pole line), approximately 5” long • Ten paper “fish” (patterns are at the end of this section and a full color version is in the “Additional Materials” envelope) • Steel paper clips to attach to fish (so they’ll be attracted to the magnetic fish line) • 1 copy per student of the Student Packet • 1 copy of the Answer Key • 1 copy of the Task Card • Unsharpened pencil or wood ruler to tie the string to (the part of the “fishing pole”) • Clear tape (to attach paper clips to fish) • The Answer Key/Rubric for the Final Assessment which the Teacher grades. It is at the end of the Teacher Information Section.

Setting Up Center 3

• The fishing pole and the magnetic fish should be pre-assembled for the magnetism activity and placed at the activity center. (Tie the string to the pencil or ruler to make a “handle and fishing line”. The fishing line and magnet should be about 3” long. Tie the magnet to the opposite end of the string to make a “fishing hook”. Tape a steel paper clip to the back of each of the 10 fish.) • Make 1 copy per student of the Student Packet • Make 1 copy of the Answer Key. Make these accessible to students but hidden from view. Optional: Laminate each answer sheet and glue/place each in a file folder marked “Answer Key”. • Make a copy of the Task Card. Optional: Laminate it and /or glue it to a file folder or other stiff material to make it stand up.

Content Reviewed

These three centers address several aspects of the effect of forces on the motion of objects. Both the types of forces and the predicted changes in motion are included. A force can stop something from moving, start moving or change speed or direction.

Forces can be divided up into contact (touching) forces and non-contact (not touching) forces. Some forces are usually one or the other, while other forces may be both. For example, gravity is an excellent example of a non-contact force. Gravity causes objects to fall down without any direct contact. Even when gravity holds an object down (like a ball resting on the ground) the contact is between the ball and the Earth. It is Earth that causes the gravitational force that holds the ball down.

The force of collision is one example of a contact force. When two objects collide, the force occurs when the objects actually touch each other. Friction is another example of a con-

tact force.

Magnetic Force is an example of a type of force that can be either a contact or non-contact force. You can use a magnet to move an object without touching it. However, when a magnet picks up and holds an object it is exerting a contact force.

The other content addressed in these centers is the idea of being able to predict how the motion of an object will change when the object experiences a force. Center 2 uses the change in speed of a car when it is pushed with a different force as an example. Other examples would be a baseball being hit with a bat, pulling an object such as sled, or having a soccer ball slowly roll to a stop because of friction.

Prerequisite Skills

Students will need the following skills to do the activity:

• Ability to set and read a stopwatch or similar timer. • Ability to scientifically describe and sometimes explain orally and in writing (in- cluding pictures) what they have observed.

Vocabulary

Non-contact force: A force that acts on an object without touching the object (e.g., magnet and gravity).

Contact force: A force that acts on an object by touching the object (e.g., collision, magnets and gravity).

Gravitational force: A force between two or more masses (such as the Earth and a person); it is always an attracting force.

Speed (of falling objects): How fast an object is moving downward.

Non-contact magnetic force: A magnetic force that acts on objects at a distance, without having to touch the object.

Contact magnetic force: A contact force exerted on ferro-magnetic objects by the magnet (attracted to the magnet).

Attract: To bring or pull toward (not away).

Repel: To push away (not attract).

Check Your Understanding Final Assessment Answer: Teacher grades

Name one contact and one non-contact force that you observed during these activities. Describe how each force affects the motion of an object.

Forces and their descriptions that might be named are:

Gravity As a non-contact force, it makes objects fall or roll down a hill or ramp without having direct contact.

Magnetism As a non-contact force, it attracts and causes certain metals and objects to move without actually touching them (like the paperclips in Magnetic Fishing).

As a contact force, it stops the motion of certain metals and other objects when they are held by the magnet (like when the paperclips were held touching the magnet).

Collision A contact force that can start, stop, speed up, slow down or change the direction of the motion of an object when it acts upon the object by coming in contact with it.

Push, Pull Any force is defined as a push or pull. A push or pull on an object can be at a distance (non-contact) such as gravitational force pulling a toy car down a ramp or a magnet pushing or pulling on another magnet or a paperclip at a distance (non-contact).

A push or pull can also be a contact force. Examples might be moving a toy car by pushing or pulling (touching) it with your hand, or using a magnet to hold a paperclip in place by touching it.

Friction Friction is a contact force that slows the motion of an object. (Although we did not deal with this force in these activities, it is a possible answer).

Rubric for Student Answer

Score Explanation 4 points Correctly identifies one contact and one non-contact force and gives a correct explanation of how each force affects the motion of an object 3 points Correctly completes 3 of the 4 parts of the question. 2 points Correctly completes 2 of the 4 parts of the question. 1 point Correctly completes 1 of the 4 parts of the question. 0 points Does not include any correct answer.

CENTER 1 RAMP ROLLING/GRAVITY & COLLISION

Forces Affecting Objects

CENTER 1 STUDENT TASK CARDS

STUDENT TASK CARDS Forces Affecting Objects

CENTER 1 TASK CARD

I can show that when an object is raised up above the floor or table top, gravitational force will make the object fall down. I can show that gravitational force is a non-contact force because it does not touch the object to make it move. I can show collision is a contact force that changes the motion of an object.

FLASK TASK

Task A Directions

1. With your partner, set up the ramp with 2 books to raise one end. If you have a folded ramp, putting binder clips at the folds may help stabilize the ramp. 2. Place the toy car at the top of the ramp in the center. Release the car down the ramp by holding your pencil across the front of the car, then quickly moving the pencil away. Practice a few times to figure out the best way to roll the car so the car stays on the ramp all the way to the bottom.

CENTER 1 TASK CARD, continued 3. After a few test runs, you are ready to time its travel time. 4. Use a stopwatch to record the time it takes for the car to travel from the top to the bottom of the ramp. If the car goes off the ramp, redo the trial. 5. Do this 2 times and record your observations each time in your Student Packet. 6. Next, place 2 more books (a total of 4) under the ramp to raise the end a little higher. Place the toy car at the top of this steeper ramp and release it to roll (fall) down the ramp. Time it. Record your observations for 2 trials in your Stu- dent Packet. 7. Place another 2 books (now a total of 6 books) under the ramp to make it still steeper. Repeat the steps above. Record your observations for 2 trials in your Student Packet. 8. Read the “Quick Facts – Forces Affecting Objects” in your Student Packet. 9. Complete “Check Your Understanding #1” in your Stu- dent Packet and check your answer in the Answer Key.

CENTER 1 TASK CARD, continued Task B Directions 1. Set up a ramp only 2 books high. Hold a book at the low end of the ramp as a barrier. 2. Roll the car down the ramp. 3. Watch what happens to the car as it hits the book. This collision is an example of a contact force because the car actually touched (made contact with) the barrier. 4. Complete “Check Your Understanding #2” in your Stu- dent Packet and check your answer in the Answer Key. 5. Complete the “Forces Affecting Objects Vocabulary Page” in your Student Packet and check your answers in the Answer Key. 6. Complete “Check Your Understanding #3” in your Stu- dent Packet and check your answer in the Answer Key.

Forces Affecting Objects

CENTER 1 STUDENT PACKET forces affecting objects NAME ______Student Packet

Follow the directions on your Task Card and complete the Data Sheet below, describing what you observed.

Data Sheet: Task A

Trial 1: Ramp, 2 Time for car to books roll down ramp Comments or observations First try

Second try

Trial 2 : Steeper Time for car to ramp, 4 books roll down ramp Comments or observations First try

Second try

Trial 3: Steepest Time for car to ramp, 6 books roll down ramp Comments or observations First try

Second try

Check the Answer Key, then read the next page.

Read the following:

Quick Facts – Forces Affecting Objects

• The force of gravity affects all objects everywhere on Earth, and to some degree everywhere in the universe.

• Gravity works at a distance, so it is a non-contact force. However, when objects are on the Earth (touching), gravity holds the objects in place or causes them to slide or roll down a slope.

• The force of gravity on Earth is an attracting force; it always pulls things downward toward the Earth. On Earth, objects in free fall (when no other forces are acting on them) fall down.

• When objects fall (roll or slide) down a ramp, the force of gravity is pulling the objects down.

• When a ramp is not as steep, the more the ramp is holding back the falling object, the slower the object will fall.

• When the ramp is steeper, the ramp will hold back less and the object will fall faster. If we made the ramp straight up and down, absolutely vertical, it would not hold the falling object back at all. So the object would be in free-fall because of the force of gravity (dis- regarding air resistance).

• A contact force affects the motion of an object by actually touching it. A collision is one type of contact force because the motion of an object (like the car rolling down the ramp) is affected by touching another object (like the car stopped because it ran into the barrier).

Now complete “Check Your Understanding #1” on the next page.

Check Your Understanding #1 Gravitational Force

1. When you roll the toy car down the ramp, is there a force that causes the car to roll down the ramp? ______. Explain your answer:

2. What do we mean when we say a force is a non-contact force?

3. Could that same force that you identified in question #1 also cause the toy car to roll upward on the ramp? ______. Why?

4. Draw a picture to describe the non-contact force and its effect on the toy car on the ramp.

Otis Says: Check Your Answer with the Answer Key!

Task B: Do the Collision Activity and answer the following questions.

Check Your Understanding #2 Collision

1. What happened to the car’s motion when it came in contact with the barrier?

2. What do we call this type of contact force?

3. What do we mean when we say a force is a contact force?

4. Draw a picture to describe the contact force in this activity and its effect on the toy car on the ramp.

Check Your Answer with the Answer Key!

VOCABULARY

For each of the following words, write a definition and draw a picture or give an example.

Non-contact Force Definition Drawing or Give an Example

Contact Force Definition Drawing or Give an Example

Gravitational Force Definition Drawing or Give an Example

Change in Motion (Speed) of Falling Objects Definition Drawing or Give an Example

Check Your Answer with the Answer Key!

Check Your Understanding #3 Ramp Rolling

In the Ramp Rolling activity, which of the following is an example of a non- contact force?

a. Push

b. Gravity

c. Friction

d. Collision

Explain why you chose that answer:

Check Your Answer with the Answer Key!

CENTER 1 ANSWER KEY forces affecting objects answer key Answer Key

Follow the directions on your Task Card and complete the Data Sheet below, describing what you observed.

Data Sheet: Task A

Trial 1: Ramp, 2 Time for car to books roll down ramp Comments or observations First try May comment on how to make a good roll, etc. Second try

Trial 2 : Steeper Time for car to ramp, 4 books roll down ramp Comments or observations First try Should be faster than Trial 1. Second try May compare to Trial 1.

Trial 3: Steepest Time for car to ramp, 6 books roll down ramp Comments or observations First try Should be faster than Trial 2. Second try May compare to Trial 1 and/or 2.

Check Your Understanding #1 Gravitational Force

Question 1: When you roll the toy car down the ramp, is there a force that causes the car to roll down the ramp? Explain your answer.

Yes. Gravity is the non-contact force that causes the car to roll down the ramp.

Question 2: What do we mean when we say a force is a non-contact force?

A non-contact force is one that acts on an object without touching it. The force works from a distance.

Question 3: Could that same force that you identified in question #1 also cause the toy car to roll upward on the ramp? Why?

No. Gravity only pulls objects down toward the Earth. Gravity is an attracting force, never a repelling force.

Question 4: Draw a picture to describe the non-contact force and its effect on the toy car on the ramp.

This could simply be a picture of a car rolling down a ramp, with some detail about the ramp, the car, and perhaps lines or something similar indicating the downward direction of the car. Perhaps an arrow or words might show the “gravity pulling downward” on the car.

Complete Task B on your Task Card.

Check Your Understanding #2 Collision

Question 1: What happened to the motion of the car when it came in contact with the barrier?

The motion was changed – it stopped. The collision with the barrier was a contact force that changed the motion of the car.

Question 2: What do we call this type of contact force?

Collision

Question 3: What do we mean when we say a force is a contact force?

It touches the object.

Question 4: Draw a picture to describe the contact force in this activity and its affect on the toy car on the ramp.

This might be a picture of the ramp with a book at the bottom and the car running into it.

Now complete the Vocabulary Words in your Student Packet.

Vocabulary

Non-contact Force Definition Drawing or Give an Example

A force that acts on an object without touching the object (e.g., magnetic and gravitational).

Contact Force Definition Drawing or Give an Example

A force that acts on an object by touching the object (e.g., collision, magnetic and gravitational).

Gravitational Force Definition Drawing or Give an Example

A force between two or more objects (such as the Earth and a person); it is always an attracting force.

Change in Motion (Speed) of Falling Objects Definition Drawing or Give an Example

How fast an object is moving downward.

Now go to “Check Your Understanding #3” in your Student Packet.

Check Your Understanding #3 Ramp Rolling

In the Ramp Rolling Activity, which of the following is an example of a non-contact force?

a. Push

b. Gravity. This is the correct answer.

c. Friction

d. Collision

Explain why you chose that answer:

A non-contact force does not touch an object, but still makes the object move. Gravity causes objects to move without touching them. When we rolled the car down the ramp, it moved down because of the force of gravity, but there was no direct gravitational contact that made it move.

Now go to Center 2 – Get Pushy.

Forces Affecting Objects

CENTER 2 - GET PUSHY

Forces Affecting Objects

CENTER 2 - GET PUSHY Student task card

Student task card Forces Affecting Objects

CENTER 2 TASK CARD

I can predict the effect of a push on the motion of an object.

FLASK TASK

Directions: 1. Place the car at the top of a ramp 2 books high. 2. Trial A: Allow it to roll down the ramp by just releasing it, not pushing it. 3. Time its travel time. Do this two times and record your results in your Student Packet. 4. Trial B: Position the car at the top of the ramp, but, this time, gently push the car as you release it. (You may want to practice pushing the car down the ramp several times). 5. Time its travel. Do this two times, and record your results in your Student Packet. 6. Complete the questions and the “Check Your Understand- ing – Get Pushy” in your Student Packet and check your answer in the Answer Key.

Forces Affecting Objects

CENTER 2 STUDENT PACKET forces affecting objects NAME ______Student Packet

Follow the directions on the Center 2 Task Card and complete the Data Sheet below.

Time for car Trial A: to roll down the Not pushing car ramp Comments or observations

First try

Second try

Time for car to Trial B: roll down the Pushing car ramp Comments or observations

First try

Second try

Answer the questions on the next page.

1. When you pushed the car down the ramp instead of just releasing it, what change did you see in the motion?

2. If you pushed the car down the ramp even harder, what would you predict would happen to the amount of time it would take to get to the bottom of the ramp?

Complete the “Check Your Understanding” on the next page.

Check Your Understanding Get Pushy

Answer the following question.

The principal’s chair has wheels. It sits on her office floor next to her desk. She pulls the chair away from her desk. What makes the chair move? a. The force of gravity on the chair. b. The force of her pull on the chair. c. Friction between her hand and the chair. d. Friction between the wheels and the floor.

Question adapted from the Ohio Department of Education, 2007. Explain why you chose that answer.

Check Your Answer with the Answer Key!

Forces Affecting Objects

CENTER 2 ANSWER KEY forces affecting objects answer key Answer Key

Get Pushy Activity Questions

Follow the directions on the Center 2 Task Card and complete the Data Sheet below.

Time for car Trial A: to roll down the Not pushing car ramp Comments or observations

First try

Second try

Time for car to Trial B: roll down the Pushing car ramp Comments or observations

First try Should be faster than Trial A. Second try

Get Pushy Activity Questions

Question 1: When you pushed the car down the ramp instead of just releasing it, what change did you see in the motion?

The “push” force exerted on the car made it go down the ramp faster.

Question 2: If you pushed the car down the ramp even harder, what would you predict would happen to the time it would take to get to the bottom of the ramp?

If you pushed the car harder, the car would move faster, its speed would be greater, and it would reach the bottom of the ramp in less time.

Flask says: Go back to your Student Packet and complete the “Check Your Understanding – Center 2 – Get Pushy.”

Check Your Understanding Center 2 - Get Pushy

The principal’s chair has wheels. It sits on her office floor next to her desk. She pulls the chair away from her desk. What makes the chair move? a. The force of gravity on the chair.

b. The force of her pull on the chair. This is the correct answer.

c. The force of her pushing downward on the chair.

d. The force of friction between the wheels and the floor.

Question adapted from materials produced by the Ohio Department of Educa- tion, 2007. Explain why you chose that answer. When the principal pulls the chair away from her desk, she is exerting a force on the chair that changes its motion. The chair changes its motion - it goes from standing still to moving – because of the force of her pull. This is the same idea as when you changed the speed of the car by exerting a force on it when you pushed it.

Now, go on to complete Center 3 – Magnetic Fishing.

Forces Affecting Objects

CENTER 3 magnetic fishing

Forces Affecting Objects

CENTER 3 student task cards

student task cards Forces Affecting Objects

CENTER 3 TASK CARD

I can demonstrate a contact and non-contact force by using a magnet “fish hook” and a magnetically attracted steel paper clip “fish.”

FLASK TASK

Directions 1. Place the paper fish in an area about 3 feet by 3 feet on a tabletop or on the floor. 2. Direct your magnetic “fishing pole” toward a fish (one at a time) so that the magnet slowly attracts the fish and holds onto it. 3. When you catch a fish, take it off the “hook” and set it aside. 4. Observe how far away from the fish you can hold your magnet and still “catch” it.

CENTER 3 TASK CARD, continued 5. Notice that there is a moment when the fish is attracted to the magnet, but is not in contact with the magnet. If you gently move your magnet from side to side, you may even be able to move the fish around without touching it. ** When the fish is drawn to the magnet before the magnet actually touches it, the magnetic force is a non-contact force. It is a non-contact force because it is not in contact with (or touching) the fish. 6. Repeat the process until all fish have been caught, care- fully observing the motion due to magnetic force. ** When the magnet catches and holds the fish, it is a contact force. So, magnetic force can be both a contact and a non- contact force. 7. As you and your partner are doing this activity, answer the questions in your Student Packet. 8. Check your answers for the Activity Questions. 9. Read “Magnetism as a Non-Contact Force Quick Facts” in your Student Packet. 10. Complete the Magnetic Force Vocabulary page and check your answers with the Answer Key.

CENTER 3 TASK CARD, continued 11. Complete “Check Your Understanding #1” and check your answers with the Answer Key. 12. Complete the “Final Assessment “ and have your teacher check your answer.

Forces Affecting Objects

CENTER 3 student Packet forces affecting objects student packet Student Packet

Activity Questions

When you are done with the Task, answer these questions:

1. Describe what you see happening with your magnetic fishing line and the fish when you “catch” the fish.

2. Draw a picture of what you see happening:

3. Why is this an example of a contact force?

4. What do you see happening with the magnetic fishing line and the fish that shows a non-contact force?

5. Draw a picture that would show what is happening with the non-contact force.

6. When fishermen catch real fish with a fishing line and hook, do you think that is a contact or a non-contact force that catches the fish? Explain your thinking.

Otis Says: Check Your Answer with the Answer Key!

Read the following before you move on.

Quick Facts - Magnetism as A Non-Contact or Contact Force

• The force from opposite poles, North and South, of two magnets attract each other. They attract when they are touching each other (contact) and when they are not touching each other (non-contact).

• The force from like poles, North and North or South and South, of two magnets repel each other. They repel when they are not touching each other (non-contact) and repel so strongly that it is difficult or impossible to make the like poles touch each other.

• Magnets can attract from a distance (non-contact) certain metal items, such as steel paper clips, iron nails and other ferro-magnetic objects. This is like what happened when your magnet could move a paperclip fish without touching it.

• Magnets can also touch (contact) those certain metal items and hold onto them and even move them from place to place. This is like what happened when you hooked your paperclip fish with your magnet.

• Ferro-magnetic refers to certain metal materials or objects that are attracted to magnets.

• Many materials or objects are not attracted or repelled by magnets, such as plastic, rubber, glass, and non-ferro-magnetic metals such as copper and aluminum.

Complete the Vocabulary Words on the next page

Vocabulary

For each of the following words, write a definition and draw picture or give an example:

Non-contact Magnetic Force Definition Drawing or Give an Example

Attract Definition Drawing or Give an Example

Repel Definition Drawing or Give an Example

Contact Magnetic Force Definition Drawing or Give an Example

Check Your Answer with the Answer Key!

Check Your Understanding #1

Answer the following question and explain your answer.

Magnetic Force is

a. A contact force

b. A non-contact force

c. Both a contact and non-contact force

Explain why you chose that answer:

Check Your Answer with the Answer Key!

Check Your Understanding Final Assessment

Think back to the Ramp Rolling, Get Pushy and Magnetic Fish- ing activities. Name one contact and one non-contact force that you observed during these activities and describe how each force affects the motion of an object.

Have Your Teacher Check This Answer!

CENTER 3 ANSWER KEY forces affecting objects answer Key Answer Key

Magnetic Fishing Activity Questions

Question 1: Describe what you see happening with your magnetic fishing line and the fish.

You should have written something about the magnet attracting (pulling) the fish (closer) even before the magnet comes close enough to touch the fish. And then when the magnet gets closer, grabbing onto and holding the fish (because the steel paperclip on the fish is attracted to the magnet).

Question 2: Draw a picture of what you see happening:

You should have shown the fish (and maybe the paperclip) and the fishing pole with the magnet and some way of depicting them coming together. A few words in the picture to label it would be good.

Question 3: Why is this an example of a contact force?

There is a steel paperclip on the fish and the magnet attracts this kind of metal and holds on to it. It is a contact force because the magnet and the fish are touching .

Question 4: What do you see happening with the magnetic fishing line and the fish that is about a non-contact force?

The magnet can pull the paperclip fish toward it even when they are not touching (non-contact) each other.

Question 5: Draw a picture that would show what is happening with the non-contact force.

You should have shown the paperclip fish moving toward the magnet on the fishing line.

Question 6: When fishermen catch real fish with a fishing line and hook, do you think that is a contact or a non-contact force that catches the fish? Explain why you think that.

This would be a contact force, because the fishing hook must actually touch the fish to hook it.

Flask says: Now read “Quick Facts – Magnetism.”

Vocabulary

Non-contact Magnetic Force Definition Drawing or Give an Example

A force that acts on an object without touching the object.

Attract Definition Drawing or Give an Example

To bring or pull toward (not away).

Repel Definition Drawing or Give an Example

To push away (not attract).

Contact Magnetic Force Definition Drawing or Give an Example

A contact force exerted on ferro- magnetic objects by the magnet (attracted to the magnet).

Now complete “Check Your Understanding #1” in your Student Packet.

Check Your Understanding #1

Magnetic Force is

a. A contact force

b. A non-contact force

c. Both a contact and non-contact force. This is the correct answer.

Explain why you chose that answer:

A magnetic force affects the motion of an object when it is touching it (contact force) and when it is not touching it (non-contact force). A magnet can also make an object move even though it is a few inches away and not in contact with the object.

Now, complete the Final Assessment in your Student Packet.