Simple Machines

Simple machines make the things we use in everyday life function.

Engineers use - and combine - simple machines to design complex devices to make our lives easier!

Simple machines are basic devices that help accomplish physical tasks with few or no moving parts. The six most common simple machines – inclined plane, wedge, screw, lever, pulley and wheel-and-axle – are designed to change the magnitude/direction of the force (remember, work = force x distance), ultimately making the task easier to perform.

The six most common simple machines

A grooved circular disk (or disks) that guide a rope or cable pulled around its perimeter. With a single pulley engineers can change the direction of an applied force, such as pulling a rope down to lift a weight up. However, using a combination of pulleys in a pulley system can change both the amount and direction of the applied effort. Engineers design large machines, like cranes, bulldozers and elevators, with a system of pulleys to manipulate huge loads with a little force supplied by a relatively small motor.


An inclined plane that is wrapped around a cylinder. Engineers use screws in a variety of ways, including fasteners that are used to attach wood or metal; lifting screws that are used to lift heavy objects and dig holes; and bolts that are used with nuts to keep things together.


A long beam that rests on a point or support called a fulcrum. By positioning the fulcrum close to a heavy object and applying an effort from far away, levers can be used to lift enormous loads with ease. The object being moved by the lever is often called the load, or output force, while the force applied to the lever is called the effort, or input force. Crowbars are a commonly-used lever that help workers and carpenters easily extract nails from wood.


An object that tapers to a thin edge and forces a substance apart. It can be used to split things apart, such as an ax, or to hold things, such as a doorstop. Engineers design modern cars and jets using the principle of a wedge to help them cut through the air by including a pointed wedge at the front.

Wheel & Axle

Composed of a circular wheel directly connected to a circular shaft or axle, this device rotates around the common axis and has the ability to increase a rotational force instead of a linear force. Engineers commonly refer to a rotational force as torque and use this simple machine to design and create the steering wheel, jet engine, mechanical gears, and even doorknobs.

Inclined Plane

A flat, sloping surface that is used for raising or moving heavy objects from one place to another. Inclined planes are used to lift loads that would otherwise be too heavy to lift straight up. The angle or the steepness of the inclined plane determines how much effort is required to move an object. The steeper the angle, the more effort is required. We see inclined planes used in ramps and switchback roads.

The simple machines used by ancient engineers to construct the pyramids in Egypt and the Colosseum in Rome are the same ones used by engineers today to build roller-coasters, skyscrapers and bridges in our modern world. We encounter simple machines in our everyday lives in devices like crowbars, wheelbarrows and highway ramps.

These simple machines leverage the unique phenomenon of mechanical advantage of the design and then engineers combine multiple simple machines to create more advanced tools like cars, bicycles, medical devices and 3D printers.

Check out the resources below filled with various sensemaking tasks grounded in exploring everyday phenomena through the use of simple machines!

Simple Machines Curricula

The engaging resources from TeachEngineering featured here, by grade band, exemplify simple machines curriculum.

Grades K-2

  • An Introduction to Inclined Planes
    An Introduction to Inclined Planes

    preview of 'An Introduction to Inclined Planes' Lesson

    Students are introduced to the concept of simple tools and how they can make difficult or impossible tasks easier. They begin by investigating the properties of inclined planes and how implementing them can reduce the force necessary to lift objects off the ground.

  • The Benefits of Inclined Planes: Heave Ho!
    The Benefits of Inclined Planes: Heave Ho!

    preview of 'The Benefits of Inclined Planes: Heave Ho!' Activity

    Why does setting up an inclined plane on the back of a truck make it easier to load and unload? What's the difference between dragging an object up a slope versus lifting an object straight into the air? Have students learn about the engineering behind the practicalities of inclined planes.

Grades 3-5

  • Solid Rock to Building Block
    Solid Rock to Building Block

    preview of 'Solid Rock to Building Block' Activity

    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

    preview of 'Powerful Pulleys' Lesson

    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...

  • Pulley'ing Your Own Weight
    Pulley'ing Your Own Weight

    preview of 'Pulley'ing Your Own Weight' Activity

    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. ...

  • Slide Right on by Using an Inclined Plane
    Slide Right on by Using an Inclined Plane

    preview of 'Slide Right on by Using an Inclined Plane' Lesson

    Students explore building a pyramid, learning about the simple machine called an inclined plane. They also learn about another simple machine, the screw, and how it is used as a lifting or fastening device.

  • Engineering: Simple Machines
    Engineering: Simple Machines

    preview of 'Engineering: Simple Machines' Lesson

    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.

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Grades 6-8

  • The Advantage of Machines
    The Advantage of Machines

    preview of 'The Advantage of Machines' Lesson

    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

    preview of 'A Simple Solution for the Circus' Activity

    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

    preview of 'Just Plane Simple' Lesson

    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

    preview of 'Tools and Equipment, Part I' Activity

    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

    preview of 'Machines and Tools, Part II' Activity

    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.

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Grades 9-12

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

    preview of 'Simple Machines and the Rube Goldberg Challenge' Maker 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

    preview of 'Splash, Pop, Fizz: Rube Goldberg Machines' Activity

    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.

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