Activity Time: 120 Minutes
Note: this lesson can easily be taught over the course of two class periods.
Period 1 - Convergent Learning Activity Period 2 - Divergent Learning Activity
Targeted Grade Level: 6 - 8
Student Grouping: Teams of up to 4 students
Additional Lesson Materials: - Curriculum Packet - Student Engineering Workbook
Kid Spark Mobile STEM Lab: Young Engineers OR Engineering Pathways
Overview: In this lesson, students will explore how fixed and movable pulleys can be used to make work easier. Then, students will work as a team to design and engineer a custom pulley system to solve a challenge.
Click here to explore the entire Kid Spark Curriculum Library.
Learning Objectives & NGSS Alignment: Define the elements and purpose of a pulley. Assemble a pulley system and calculate its mechanical advantage. Design and engineer a custom pulley system to solve a challenge. Scientific/Engineering Practice - Asking questions & defining problems Crosscutting Concept - Systems & system models
Pre-Lesson Preparation: 1. Prepare enough lesson materials for each team. (Curriculum Packets, Student Engineering Workbooks)
2. Get hands-on. Build the pulley model and review the lesson content.
3. Prepare an example solution for the design and engineering challenge. Curriculum Packet - Page 10
Convergent Learning Activity: 1. Introduce students to the elements and purpose of a pulley. Note: it may be helpful if the instructor already has the
pulley system built for demonstration. Curriculum Packet - Pages 1 - 2
2. Instruct teams to assemble the pulley system model and weights. Curriculum Packet - Pages 3 - 7
3. Work with teams as they test the weights on the fixed pulley system. Note: the point of this test is to demonstrate that since the weights are equal, the weight of one isn't enought to overcome the weight of the other. Curriculum Packet - Page 8
4. Work with teams as they test the movable pulley system. Note: the point of this test is to demonstrate how a movable pulley system can be used to reduce the amount of effort required to raise a load. In this example, weight 1 (effort) travels a further distance in order to reduce the amount of effort needed to raise weight 2 (load). Curriculum Packet – Page 8
5. Work with teams as they calculate the mechanical advantage of the fixed and movable pulley systems. Curriculum Packet - Page 9
6. Challenge teams to try and modify the movable pulley system to increase the mechanical advantage from 2:1 to 3:1. See solution on next page.
Divergent Learning Activity: 1. Review the Design & Engineering Challenge with teams. Curriculum Packet - Page 9
2. Instruct teams to use the Kid Spark Design & Engineering Process to develop a solution to the challenge. Student Engineering Workbook - Page 3
3. Instruct teams to fill out the design specification after they have completed their project. Student Engineering Workbook - Page 4
4. Review the challenge rubric with teams so they understand how they will be evaluated for the project. Student Engineering Workbook - Page 5
5. Consider setting strict time boundaries for the divergent learning activity (see example below). Keep in mind that teams won't always complete a design that works or looks as intended. That's alright! Students can learn a lot by reflecting on their experience and considering what they might have done differently if they had more time or could start the project over.
a. Review the challenge with teams. (2 minutes)
b. Teams work through the design and engineering process to create a design. (30 minutes)
c. Teams complete design specification. (10 minutes)
d. Teams present designs to class. Each team has 1 minute max to present. (10 minutes)
e. Lab cleanup. (8 minutes)
Lesson Closure: 1. Project presentations - Instruct each team to share the design they created with the rest of the class. 2. Lab cleanup - After teams have finished their presentations, instruct them to disassemble their designs and pack all
engineering materials back into the labs correctly. Note: each lab should include a laminated inventory and organization guide to help students pack engineering materials back correctly.
3. Lesson reflection - If time permits, do a quick recap/review of the lesson.
Assessment/Evaluation:
A. Student Engineering Workbook (9 Points) B. Design & Engineering Challenge (25 Points)
3:1 Pulley
Team Members:
1. 3.
Total Points
/9 ptsWorkbook:
Key Terms
Simple Machine: A device that transmits or modifies force or motion.
Pulley: A simple machine consisting of a wheel with a grooved rim in which a pulled cable can change the direction of the pull an thereby lift a load.
Mechanical Advantage: The amount a machine multiplies force.
Force: A push or a pull.
Work: Using a force to move an object a distance.
Effort: A force applied to a machine to do work.
Load: The object or weight being moved or lifted.
What is a Pulley? Write the correct answer in the spaces provided.
1. Identify the three elements of a pulley.
A. _________________________________ B. _________________________________
C. _________________________________
2. As a team, discuss and/or research real-world examples of a pulley. Write two examples in the spaces provided.
Example 1 - _______________________________________________________
Example 2 - _______________________________________________________
The Purpose of a Pulley Write the correct answer in the spaces provided.
3. What are two of the primary purposes of a pulley?
A. _______________________________________________________
B. _______________________________________________________
Load
Effort
Cable
4
Building and Testing a Pulley Place a check in each box as each step is completed. 4. Follow the step-by-step instructions to assemble a pulley system. Curriculum Packet - Pages 3 - 5
5. Follow the instructions to assemble the weights for the pulley system. Curriculum Packet - Pages 6 - 7
6. Test the weights on the fixed pulley system.
Why did the weights balance each other equally? ________________________________________________________________
_________________________________________________________________________________________________________________
_________________________________________________________________________________________________________________
7. Test the weights on the movable pulley system.
_________________________________________________________________________________________________________________
_________________________________________________________________________________________________________________
_________________________________________________________________________________________________________________
Calculating the Mechanical Advantage of a Pulley Write the correct answer in the spaces provided.
8. Calculate the mechanical advantage of the movable pulley system.
Distance the effort travels - ____________ cm Distance the load travels - ____________ cm
Mechanical Advantage - ____________ # of strings connected to the movable pulley - ____________
Instructions: Place a check in each box as each step is completed.
9. As a team, modify the movable pulley system to increase the mechanical advantage to 3:1.
X
X
The weights balance each other equally because they are the
same size and weight. In a fixed pulley system, when one weight is pulled down, the other weight travels an
X
equal distance in the opposite direction. A fixed pulley system does not multiply force.
In a movable pulley system, mechanical advantage is created by trading distance for speed. Weight 1 (effort)
is traveling a further distance in order to raise weight 2 (load).
X
20
2:1
10
2
X
5
Design & Engineering Challenge Follow each step in the design & engineering process to develop a solution to the challenge. Place a check in each box as each step is completed. Fill in the blanks when necessary.
1. Identify The Challenge
Choose the best design.
3. Build A Prototype
4. Test & Improve The Design
Look for opportunities to improve the design. (Is it practical, proportional, etc..)
Review challenge specifications/criteria and grading rubric.
5. Explain The Design
Determine the specifications of the design that was created. Student Engineering Workbook - Page 4
Discuss the following items with your team and be prepared to share with the rest of the class. a. How did the team arrive at the final design solution? Discuss how each step in the Design & Engineering process was used to develop the design. b. Is the design realistic and well-proportioned?
c. How did each team member contribute towards the overall design? Do you feel like everyone had an equal opportunity to contribute in the creative process?
d. Is the team prepared to share detailed specifications of the design to others?
X Develop a new product or design that utilizes a pulley.
X
X
X
X
X
X
X
X
X
6
Design Specification Determine the specifications of the completed design/project. Teams can use these specifications as they prepare to present their design to others.
cm
Length Depth Height
Purpose:
Engineering Notes: (How does the design work? What simple machines or mechanisms are included in the design? What is the total mechanical advantage of the design?)
What is the product or design that was created?
What is the purpose of the design? What problem does it solve? Why was it created?
How does the design work? Are there any key engineering materials that make the design function well?
Various Various Various
7
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 on page 3?
Design Specification: Did the team complete the design specification on page 4?
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?
55-01192-204
Every member of the team contributed
Great design/great aesthetics
Good design/good aesthetics
Team did not work together
Presentation
Points
Good presentation/ well explained
Poor presentation/ poor explanation
No presentation/ no explanation
Completed 4 steps of the process
Completed 3 steps of the process
Completed 2 or fewer steps of the process
Column Total Column Total Column Total Column Total
Total Points