Math of Mechanical Advantage - Pulleys
Objectives
Students will:
• Learn about pulleys and pulley systems.
• Learn how using multiple pulleys can dramatically reduce the required amount of work.
• Learn how pulley systems are used in machines and impact everyday life.
• Explain a 2:1 pulley system and understand that that ratio denotes the velocity
(or) movement ratio.
• Learn about teamwork and problem solving in groups.
Suggested Grade Levels:
3rd – 8th grades
Subject Areas
Science, Technology, Engineering, Mathematics
Timeline
50 – 60 minutes
Standards
NGSS Standards
• 3-PS2-1. Plan and conduct an investigation to provide evidence of the effects of
balanced and unbalanced forces on the motion of an object.
• 3-5-ETS1-1. Define a simple design problem reflecting a need or a want that includes
specific criteria for success and constraints on materials, time, or cost.
• 3-5-ETS1-2. Generate and compare multiple possible solutions to a problem based on
how well each is likely to meet the criteria and constraints of the problem.
• 3-5-ETS1-3. Plan and carry out fair tests in which variables are controlled and failure
points are considered to identify aspects of a model or prototype that can be improved.
• MS-PS2-2. Plan an investigation to provide evidence that the change in an object’s
motion depends on the sum of the forces on the object and the mass of the object.
• MS-ETS1-1. Define the criteria and constraints of a design problem with sufficient
precision to ensure a successful solution, taking into account relevant scientific
principles and potential impacts on people and the natural environment that may limit
possible solutions.
• MS-ETS1-2. Evaluate competing design solutions using a systematic process to
determine how well they meet the criteria and constraints of the problem.
21st Century Essential Skills
● Learning Skills
o Critical Thinking, Analysis, Creativity, Collaboration, Communication
Revised: 06/2020
Confidential and Proprietary to the Space Foundation
, ● Literacy Skills
o Information, Media, Technology, Environmental
● Life Skills
Flexibility,Leadership, Initiative, Productivity, Social, Public Speaking, Global
Awareness, Listening
Background
The Space Shuttle, the most complex machine ever built, weighs almost four and one-half
million pounds. How does NASA lift the parts of the shuttle to join them together, and then move
the entire assembly onto the launch pad? What if I told you that this can be done with
technology that goes back thousands of years?!?!?
The wheel pulley was invented around 300 B.C., and has been in use ever since, impacting the
way humans live, work, and play. Simple machines are devices with few or no moving parts that
are used to modify motion and force in order to perform work, including: the inclined plane,
lever, wedge, wheel and axle, pulley, and screw.This activity will discuss and demonstrate a
pulley system, as well as cover forces, ratios, and mechanical advantage. In addition, students
will discover that complex machines are ‘simply’ combinations of simple machines.
By placing a strongly anchored pulley above an object being lifted, humans can lift heavy
objects much easier. By attaching another pulley to that same load, and then feeding the cord
through a redirect pulley above, mechanical advantage has been applied. By doing this, the
pulley system has effectively cut the load being lifted in half in terms of how much force is
required to lift the load.
This lesson is the perfect way to introduce simple machines to students, learning how more
math equates less work, all thanks to mechanical advantage, along the way!
Vocabulary
Cord, Force, Mechanical advantage, Simple Machine, Pulley, Ratio, Redirect, Velocity (or)
Movement Ratio
Materials
• Pulleys – 1 set per class
• Cords – 15 to 20 strands per class (3 ½ to 4 meters worth PLUS an extra strand of cord
for the redirect line. It is important to have excess cord available for students to create
connection loops as necessary.)
• C-Clamps – 1 set per class
• Carabiners – 1 set per class
• Tape measure – 1 per group
• Stacks of books – 1 stack per group
Revised: 06/2020
Confidential and Proprietary to the Space Foundation
Objectives
Students will:
• Learn about pulleys and pulley systems.
• Learn how using multiple pulleys can dramatically reduce the required amount of work.
• Learn how pulley systems are used in machines and impact everyday life.
• Explain a 2:1 pulley system and understand that that ratio denotes the velocity
(or) movement ratio.
• Learn about teamwork and problem solving in groups.
Suggested Grade Levels:
3rd – 8th grades
Subject Areas
Science, Technology, Engineering, Mathematics
Timeline
50 – 60 minutes
Standards
NGSS Standards
• 3-PS2-1. Plan and conduct an investigation to provide evidence of the effects of
balanced and unbalanced forces on the motion of an object.
• 3-5-ETS1-1. Define a simple design problem reflecting a need or a want that includes
specific criteria for success and constraints on materials, time, or cost.
• 3-5-ETS1-2. Generate and compare multiple possible solutions to a problem based on
how well each is likely to meet the criteria and constraints of the problem.
• 3-5-ETS1-3. Plan and carry out fair tests in which variables are controlled and failure
points are considered to identify aspects of a model or prototype that can be improved.
• MS-PS2-2. Plan an investigation to provide evidence that the change in an object’s
motion depends on the sum of the forces on the object and the mass of the object.
• MS-ETS1-1. Define the criteria and constraints of a design problem with sufficient
precision to ensure a successful solution, taking into account relevant scientific
principles and potential impacts on people and the natural environment that may limit
possible solutions.
• MS-ETS1-2. Evaluate competing design solutions using a systematic process to
determine how well they meet the criteria and constraints of the problem.
21st Century Essential Skills
● Learning Skills
o Critical Thinking, Analysis, Creativity, Collaboration, Communication
Revised: 06/2020
Confidential and Proprietary to the Space Foundation
, ● Literacy Skills
o Information, Media, Technology, Environmental
● Life Skills
Flexibility,Leadership, Initiative, Productivity, Social, Public Speaking, Global
Awareness, Listening
Background
The Space Shuttle, the most complex machine ever built, weighs almost four and one-half
million pounds. How does NASA lift the parts of the shuttle to join them together, and then move
the entire assembly onto the launch pad? What if I told you that this can be done with
technology that goes back thousands of years?!?!?
The wheel pulley was invented around 300 B.C., and has been in use ever since, impacting the
way humans live, work, and play. Simple machines are devices with few or no moving parts that
are used to modify motion and force in order to perform work, including: the inclined plane,
lever, wedge, wheel and axle, pulley, and screw.This activity will discuss and demonstrate a
pulley system, as well as cover forces, ratios, and mechanical advantage. In addition, students
will discover that complex machines are ‘simply’ combinations of simple machines.
By placing a strongly anchored pulley above an object being lifted, humans can lift heavy
objects much easier. By attaching another pulley to that same load, and then feeding the cord
through a redirect pulley above, mechanical advantage has been applied. By doing this, the
pulley system has effectively cut the load being lifted in half in terms of how much force is
required to lift the load.
This lesson is the perfect way to introduce simple machines to students, learning how more
math equates less work, all thanks to mechanical advantage, along the way!
Vocabulary
Cord, Force, Mechanical advantage, Simple Machine, Pulley, Ratio, Redirect, Velocity (or)
Movement Ratio
Materials
• Pulleys – 1 set per class
• Cords – 15 to 20 strands per class (3 ½ to 4 meters worth PLUS an extra strand of cord
for the redirect line. It is important to have excess cord available for students to create
connection loops as necessary.)
• C-Clamps – 1 set per class
• Carabiners – 1 set per class
• Tape measure – 1 per group
• Stacks of books – 1 stack per group
Revised: 06/2020
Confidential and Proprietary to the Space Foundation
