Applications in Design & Engineering: Simple Machines Curriculum

v2.4 Applications in Design & Engineering: Simple Machines Curriculum Packet

Overview: In this lesson, students will assemble three different types of levers and learn Activity Time: how to calculate the mechanical advantage of each. Then, students will work 120 Minutes as a team to design and engineer a custom catapult that includes a lever. Targeted Grade Level:

Click here to explore the entire Kid Spark Curriculum Library. 6 - 8 Student Grouping: Learning Objectives & NGSS Alignment: Teams of up to 4 students Define the elements and purpose of a lever. Additional Lesson Materials: Calculate the mechanical advantage of different types of levers. - Teacher Lesson Plan Design and engineer a custom catapult that includes a lever. - Student Engineering Workbook

Scientific/Engineering Practice - Constructing explanations & designing solutions Kid Spark Mobile STEM Lab: Crosscutting Concept - Patterns Young Engineers OR Engineering Pathways

Convergent Learning Activity: 1. The Elements and Purpose of a Lever A lever is a simple machine that consists of a rigid beam (lever arm) that pivots on a fulcrum. It is used to redirect motion, create mechanical advantage to make work easier, or increase output speed to make a load move faster.

Fulcrum Rigid Beam (lever arm)

2. Types of Levers First Class Lever In a first class lever, the fulcrum is located between the effort and the load. A first class lever can be used to reduce the amount of effort needed to raise a load by placing the fulcrum closer to the load, or to increase output speed by placing the fulcrum closer to the effort.

Effort

Load Lever Arm Fulcrum

1 Second Class Lever In a second class lever, the load is located between the effort and the fulcrum. The amount of effort needed to raise a load is reduced as the load is placed closer to the fulcrum. A second class lever does not change the direction of motion because the effort and the load move in the same direction.

Load

Lever Arm Effort Fulcrum

Third Class Lever In a third class lever, the effort is applied between the load and the fulcrum. The amount of effort needed to raise the load is reduced as the effort is applied closer to the load. A third class lever is primarily used to increase output speed, which increases as the effort is applied closer to the fulcrum.

Load

Lever Arm

Effort Fulcrum

2 Instructions Follow the step-by-step instructions to assemble a first class lever.

1 2

2x 2x 4x 2x 2x 2x Beam Half Beam Block Half Beam Block Axle Block

1x 2x 2x Beam Snap-In Wheel Block

3 3. Testing and Modifying a First Class Lever Follow the instructions to test and modify the first class lever.

Testing the First Class Lever In this example, the fulcrum is been centered between weight 1 (effort) and weight 2 (load). Lift weight 1 (effort) as high as possible and let go. Observe how nothing Weight 1 - Effort happens. This is because the two weights balance each other equally.

Weight 2 - Load

Effort

Load

Fulcrum

Modifying the First Class Lever In a first class lever, the amount of effort needed to raise a load is reduced as the fulcrum is moved closer to the load. Move the fulcrum 2 openings towards weight 2 (load) as shown in the figure to the right. Now, lift weight 1 (effort) as high as possible and let go. Observe how weight 1

(effort) drops to the base, and weight 2 (load) is raised to Weight 2 - Load its highest position. In this example, the fulcrum is closer to Weight 1 - Effort the load than it is to the effort. This modification allows weight 1 (effort) to travel a further distance and raise weight 2 (load). Observe how far weight 1 (effort) travels in relation to weight 2 (load).

Effort

Load

Fulcrum

4 4. Calculating Mechanical Advantage in a First Class Lever The main purpose of a simple machine is to make work easier. This is done by either redirecting motion or creating mechanical advantage. Mechanical advantage exists when the output force of a machine is greater than the input force that was applied to it. To accomplish this, the machine must trade increased time or distance for reduced effort. The mechanical advantage gained using a lever is called leverage.

A first class lever can be used create mechanical advantage by placing the fulcrum closer to the load. To calculate how much mechanical advantage is in a first Output Distance - Input Distance - class lever, divide the input distance (distance from the 4 cm 12 cm effort to the fulcrum) by the output distance (distance from the load to the fulcrum).

In the modified first class lever, the input distance was Weight 2 - Load Weight 1 - Effort 6 blocks (12 cm), and the output distance was 2 blocks (4 cm). Divide 12/4 and this will give a mechanical Fulcrum advantage of 3:1. This lever is able to output three times the amount of force that is applied to it. Weight 1 (effort) will travel three times the distance of weight 2 (load) in order to reduce the amount of effort needed to raise the load.

Input distance (effort to fulcrum) Mechanical Advantage = Output distance (load to fulcrum)

5 Instructions Follow the step-by-step instructions to assemble a second class lever.

1 2

2x 2x 4x 2x 2x 2x Beam Half Beam Block Half Beam Block Axle Block

1x 2x 2x Beam Snap-In Wheel Block

6 5. Testing and Modifying a Second Class Lever Follow the instructions to test and modify the second class lever.

Testing the Second Class Lever In a second class lever, the load is placed between the fulcrum and the effort. In this example, when weight 1 Weight 2 - Load (effort) is raised, weight 2 (load) is raised in the same direction.

Weight 1 - Effort Load

Effort Fulcrum

Modifying the Second Class Lever In a second class lever, the amount of effort needed Weight 2 - Load to raise a load is reduced as the load is moved closer to the fulcrum. Move weight 2 (load) 3 openings towards the fulcrum as shown in the figure to the right. Lift weight 1 (effort) to raise weight 2 (load). Weight 1 - Effort There should be a noticeable difference in the amount of effort needed to raise the load. As the load is moved closer to the fulcrum, the effort will travel a further distance to raise the load. Observe how far weight 1 (effort) travels in relation to weight 2 (load).

Load

Effort Fulcrum

7 6. Calculating Mechanical Advantage in a Second Class Lever The main purpose of a simple machine is to make work easier. This is done by either redirecting motion or creating mechanical advantage. Mechanical advantage exists when the output force of a machine is greater than the input force that was applied to it. To accomplish this, the machine must trade increased time or distance for reduced effort. The mechanical advantage gained using a lever is called leverage.

A second class lever can be used create mechanical Output Distance - advantage by placing the load closer to the fulcrum. To 2 cm Input Distance - calculate how much mechanical advantage is in a second 14 cm class lever, divide the input distance (distance from the effort to the fulcrum) by the output distance (distance from Weight 2 - Load the load to the fulcrum).

In the second class lever that was built and modified, the input distance was 7 blocks (14 cm), and the output distance Weight 1 - Effort was 1 block (2 cm). Divide 14/2 and this will give a mechanical advantage of 7:1. This lever is able to output seven times the Fulcrum amount of force that is applied to it. Weight 1 (effort) will travel seven times the distance of weight 2 (load) in order to reduce the amount of effort needed to raise the load.

Input distance (effort to fulcrum) Mechanical Advantage = Output distance (load to fulcrum)

8 Instructions Follow the step-by-step instructions to assemble a third class lever.

1 2

2x 2x 4x 2x 2x 2x Beam Half Beam Block Half Beam Block Axle Block

1x 2x 2x Beam Snap-In Wheel Block

9 7. Testing and Modifying a Third Class Lever Follow the instructions to test and modify the third class lever.

Testing the Third Class Lever In a third class lever, the effort is applied between the Weight 2 - Load fulcrum and the load. In this example, when weight 1 (effort) is raised, weight 2 (load) is raised in the same direction. The amount of effort needed to raise a load is reduced as the effort is applied closer to the load.

Weight 1 - Effort

Load

Fulcrum Effort

Modifying the Third Class Lever The primary purpose of a third class lever is to increase output speed. Move weight 1 (effort) four Weight 2 - Load spaces towards the fulcrum as shown in the image to the right. In this example, when weight 1 (effort) is raised, weight 2 (load) is raised in the same direction. As the effort is applied closer to the fulcrum, the load Weight 1 - Effort will travel a further distance than the effort in the same amount of time. Observe how far weight 2 (load) travels in relation to weight 1 (effort).

Load

Fulcrum Effort

10 8. Calculating Mechanical Advantage in a Third Class Lever The main purpose of a simple machine is to make work easier. This is done by either redirecting motion or creating mechanical advantage. Mechanical advantage exists when the output force of a machine is greater than the input force that was applied to it. To accomplish this, the machine must trade increased time or distance for reduced effort. The mechanical advantage gained using a lever is called leverage.

To calculate how much mechanical advantage is in a third class lever, divide the input distance (distance Output Distance - from the effort to the fulcrum) by the output distance 14 cm (distance from the load to the fulcrum). Weight 2 - Load Input Distance - 2 cm In the third class lever that was built and modified, the input distance was 1 block (2 cm), and the output distance was 7 blocks (14 cm). Divide 2/14 and this will give a mechanical advantage of 0.14:1. This means that weight 2 (load) will travel around seven (1 ÷ 0.14 = 7.14) Weight 1 - Effort units of measurement for every one unit of measurement weight 1 (effort) travels in the same amount of time. The mechanical advantage of a third class lever will always be Fulcrum less than 1, which means it is not actually creating any mechanical advantage. Its primary purpose is to increase output speed. Output speed is increased as the effort is applied closer to the fulcrum.

Input distance (effort to fulcrum) Mechanical Advantage = Output distance (load to fulcrum)

11 Divergent Learning Activity:

Scenario: Kid Spark Engineering is currently accepting proposals for new and creative product inventions or innovations.

Design & Engineering Challenge: Develop a new product or design that utilizes a lever. See example below.

Specifications/Criteria: 1. Students will work in teams of up to 4 to design and engineer a new product or design that serves a specific purpose. Teams can invent something completely new or improve an already existing product. 2. Teams must work through each step of the design & engineering process to develop a solution to the challenge. 3. Teams must utilize a lever in the design. Teams should be able to identify what type/class of lever is being used. 4. Teams must determine the mechanical advantage of the lever in their design. 5. Teams must determine the overall dimensions of the design (length, depth, and height). 6. With each building component costing $2, determine the total cost of the design.

Example Idea:

Product Innovation/Invention: Catapult

Purpose: Fun, ball-launching mechanism Distance Gauge Design Notes: The catapult includes a distance gauge that can be used to consistently launch balls to targets Height - at multiple distances. The catapult includes a first class 28 cm lever (fulcrum is between the effort and the load). The distance from the effort to the fulcrum is 8 cm, and the distance from the load to the fulcrum is 2 cm. This gives Depth - 10 cm the lever a total mechanical advantage of 4:1. Length - 14 cm Dimensions: 14 cm x 10 cm x 28 cm (L x D x H)

Total Mechanical Advantage: 4:1

Effort Material Cost: 40 components x $2 = $80

Load Fulcrum

12 Challenge Evaluation When teams have completed the design & engineering challenge, it should be presented to the teacher and classmates for evaluation. Teams will be graded on the following criteria:

Design and Engineering Process: Did the team complete each step of the design and engineering process?

Design Specification: Did the team complete the design specification?

Team Collaboration: How well did the team work together? Can each student describe how they contributed?

Design Quality/Aesthetics: Is the design of high quality? Is it structurally strong, attractive, and well proportioned?

Presentation: How well did the team communicate/explain all aspects of the design to others?

Advanced Proficient Partially Proficient Not Proficient Grading Rubric 5 Points 4 Points 3 Points 0 Points

Design & Engineering Completed all 5 steps of Completed 4 steps of the Completed 3 steps of the Completed 2 or fewer Process the process process process steps of the process

Complete/well-detailed Complete/opportunities Incomplete/opportunities Incomplete Design Specification and of high quality for improvement for improvement

Team Collaboration Every member of the Most members of the Few members of the Team did not work team contributed team contributed team contributed together

Design Quality/ Great design/great Good design/good Average design/ Poor design/poor Aesthetics aesthetics aesthetics average aesthetics aesthetics

Great presentation/ Good presentation/ Poor presentation/ No presentation/ Presentation very well explained well explained poor explanation no explanation

Points

Total Points /25

13 Building Basics The following tips will be helpful when using Kid Spark engineering materials.

Connecting/Separating ROK Blocks:

ROK Blocks use a friction-fit, pyramid and opening system to connect. Simply press pyramids into openings to connect. To separate blocks, pull apart.

Connecting/Disconnect Smaller Engineering Materials:

Smaller engineering materials use a tab and opening system to connect. Angle one tab into the opening, and then snap into place. To disconnect, insert key into the engineered slot and twist.

Snapping Across Openings:

Materials can be snapped directly into openings or across openings to provide structural support to a design. This will also allow certain designs to function correctly.

Attaching String:

In some instances, string may be needed in a design. Lay string across the opening and snap any component with tabs or pyramids into that opening. Be sure that the tabs are perpendicular to the string to create a tight fit.

Measuring: 2cm

The outside dimensions of a basic connector block are 2 9 Openings cm on each edge. This means the length, depth, and height 4cm 2cm are each 2 cm. To determine the size of a project or build in centimeters, simply count the number of openings and 18cm 4cm 4cm multiply by two. Repeat this process for length, depth, and 2cm height.

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