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# Pulleys

Pulleys are the basis of the modern machines we use every day.
Engineers harness the power of pulleys by designing processes and mechanisms that help us achieve difficult tasks.

Thousands of years ago, early engineers used pulleys to help with construction of structures of monumental proportions, such as aqueducts, monuments and even pyramids. Today, we use pulleys to perform a variety of useful everyday tasks like opening window blinds or operating a garage door.

Engineers combine multiple pulleys into a pulley system in order to either redirect the force or reduce the amount of force required to lift an object. A pulley is one of the six simple machines that help make difficult tasks possible by leveraging the engineering phenomenon of mechanical advantage of the design.

A pulley is a system of rope looped over one or more wheels to make it easier to lift heavy objects. Pulling the rope downward creates an upward force on the load.

There are three basic systems of pulleys:
A fixed pulley has a wheel that is secured in a single spot and changes the direction of the force needed to lift an object. The pulley itself stays in place while the load moves with the rope.
A movable pulley has a pulley attached to the object; one end of the rope is attached to a fixed point and the other end of the rope is free.
A compound pulley is a combination of a fixed and movable pulley to maximize the mechanical advantage of the system.

Understanding how pulleys work allows modern engineers to design machines like elevators, cranes, bulldozers and more!

Pulley Curricula

The engaging resources from TeachEngineering featured here, by grade band, exemplify pulley curricula.

• Coming Soon!

• Solid Rock to Building Block
Solid Rock to Building Block

Students continue their pyramid building journey, acting as engineers to determine the appropriate wedge tool to best extract rock from a quarry and cut into pyramid blocks. Using sample materials (wax, soap, clay, foam) representing rock types that might be found in a quarry, they test a variety of...

• Powerful Pulleys
Powerful Pulleys

Students learn how a pulley can be used to change the direction of applied forces and move/lift extremely heavy objects, and the powerful mechanical advantages of using a multiple-pulley system. Students perform a simple demonstration to see the mechanical advantage of using a pulley, and they ident...

Using common materials (spools, string, soap), students learn how a pulley can be used to easily change the direction of a force, making the moving of large objects easier. They see the difference between fixed and movable pulleys, and the mechanical advantage gained with multiple/combined pulleys. ...

• The Power of Mechanical Advantage

Students learn about the mechanical advantage offered by pulleys in an interactive and game-like manner. Using a LEGO® MINDSTORMS® robotics platform and common hardware items, students build a mechanized elevator system.

• Engineering: Simple Machines
Engineering: Simple Machines

Students are introduced to the six types of simple machines — the wedge, wheel and axle, lever, inclined plane, screw, and pulley — in the context of the construction of a pyramid, gaining high-level insights into tools that have been used since ancient times and are still in use today.

In this lesson, students learn about work as defined by physical science and see that work is made easier through the use of simple machines. Already encountering simple machines everyday, students will learn about their widespread uses in improving everyday life.

• A Simple Solution for the Circus
A Simple Solution for the Circus

In this activity, students are challenged to design a contraption using simple machines to move a circus elephant into a rail car.

• Just Plane Simple
Just Plane Simple

This lesson introduces students to three of the six simple machines used by many engineers. These machines include the inclined plane, the wedge and the screw.

• Tools and Equipment, Part I
Tools and Equipment, Part I

Students act as engineers creating a design for a ramp at a construction site by measuring four different inclined planes and calculating the ideal mechanical advantage versus the actual mechanical advantage of each.

• Machines and Tools, Part II
Machines and Tools, Part II

In this activity, students gain first-hand experience with the mechanical advantage of pulleys. Students are given the challenge of helping save a whale by moving it from an aquarium back to its natural habitat into the ocean.

• Simple Machines and the Rube Goldberg Challenge
Simple Machines and the Rube Goldberg Challenge

Students research and learn about simple machines and other mechanisms through learning about a Rube Goldberg machine. Student teams design and build their own Rube Goldberg devices that incorporate at least six simple machines. This project is open-ended with much potential for creativity and fun.

• Splash, Pop, Fizz: Rube Goldberg Machines
Splash, Pop, Fizz: Rube Goldberg Machines

Refreshed with an understanding of the six simple machines; screw, wedge, pully, incline plane, wheel and axle, and lever, student groups receive materials and an allotted amount of time to act as mechanical engineers to design and create machines that can complete specified tasks.

• Flying T-Shirts
Flying T-Shirts

During this engineering design/build project, students investigate many different solutions to a problem. Their design challenge is to find a way to get school t-shirts up into the stands during home sporting events. They follow the steps of the engineering design process to design and build a usabl...

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