How are skyscrapers built? What makes it easy to chop up vegetables? What makes a propeller on an airplane turn? Simple machines make the things in everyday life work. Scientists define a simple machine as a device that alters either the direction or force of an object. In other words, they magnify, or enlarge, the amount of force that someone can apply to an object so that it takes less work to move it. These simple machines are often used in more complex devices, like airplanes and cranes. There are six primary types of simple machines: pulley, screw, inclined plane, wheel and axle, wedge, and lever. These simple machines are used in more complex devices every day, making tasks much easier.

Simple Machines

Simple machines make tasks simpler by reducing the amount of effort it takes for humans to perform certain tasks.

Overview of Simple Machines

Levers, pulleys, and inclines all have one thing in common: they reduce the amount of energy it takes for human to move or lift objects. This site explains the terms used when talking about simple machines and what students need to know about them.

Simple Machines and Machinery

For older students, this introduction to machines explains how they work as well as the difference between machines, simple machines, and mechanisms.

* *Examples of Simple Machines

See examples of how the simple machines are used in things people use every day.

* *Gadget or Simple Machine?

How many everyday gadgets are actually simple machines at work?

All About Simple Machines 

This collection of links has a lot of information about simple machines.

Simple Machines Explained (PDF)

Simple machines are explained here so that students can understand how they help perform tasks more easily.

Pulleys At Work 

Find out the purpose of a pulley and a variety of ways to use them. There’s also a list of common machines which use pulleys as part of their mechanism.

* *Build a Pulley 

Want to build a pulley? Go to this website to learn not only how to build one, but which one to build for the particular task.

Pulleys All Around Us 

Pulleys are all around. See some examples of simple, everyday items that use pulleys, like window blinds.

Pulley Experiments 

Want to do some simple experiments with pulleys? All it takes is some simple household items, like a rope, a broom, and a friend.

Overview of the Screw 

This site gives a basic overview of how a screw works.

* *Wedges and Screws 

Wedges and screws sometimes work together. See how at this link.

Diagram of an Inclined Plane 

Georgia State University has a great diagram of an inclined plane, explaining how it works.

Interactive Inclined Plane 

This interactive page shows an inclined plane at work.

Galileo Experiments 

See Galileo’s simple experiment with inclined planes that anyone can reproduce.

Uses of Inclined Planes

Although an inclined plane is probably the simplest of the simple machines, it is used everywhere, from wheelchair ramps to slides on the playground. See some more examples of everyday uses of an inclined plane.

Inclined Plane 

How does an inclined plane work? Learn how here.

Wheel and Axle 

This site provides a brief overview of how a wheel and axle works.

* *Egyptians and the Wheel and Axle 

Did Egyptians use a wheel and axle simple machine to build the pyramids? The author of this article thinks so.

How Does a Wheel and Axle Work? 

How does a wheel and axle save on energy to move things? This site shows how.

* *Wheel and Axle (PDF)

Find out about the wheel and axle and how it is used, along with information about other simple machines.

Wedges Everywhere 

Wedges are everywhere, even in things people don’t usually think of. For instance, a knife is a wedge. Discover how a wedge works and more places wedges can be found.

Make a Wedge (PDF)

Want to make a wedge for an experiment? This step-by-step guide shows how.

Experiments With Simple Machines 

Explore simple machines, including the wedge, with these experiments.

Use a Wedge to Solve a Problem 

This project takes kids to Egypt where they must solve problems using a wedge.

* *Lever Basics (PDF)

Learn about the three classes of levers.

Three Types of Levers 

A lever is an important simple machine. There are three different types, all of which are used every day in items like hammers and crowbars. Find out more from this link.

* *Lever Diagrams 

Sometimes a picture is needed to understand something. This site has clear diagrams demonstrating how a lever works.

* *All About Levers 

Explore the things that can be done with levers. They are everywhere, even on the playground.

Build a Lever 

Building a lever is fun. Find out how to do it here.

Test Your Lever Knowledge

Think it’s easy to tell the three classes of levers apart? This fun game will put that knowledge to the test.

Information About The Six Simple Machine Types

This site not only has information about simple machines, but there’s also links to even more information.

Interactive Simple Machines

This fun, interactive, website demonstrates how simple machines are used all over the house.

Let’s Build Using Simple Machines (PDF)

Ready to build something that uses simple machines? This project guide will get a young inventor started.

* *Rube Goldberg Machines

Rube Goldberg made fantastic inventions which used simple machines to do everyday tasks. This interactive game lets kids build machines like Goldberg’s.