Simple Machines: Introduction

Machine performing work


What is a machine? Most people think of a machine as a large and noisy invention with lots of moving parts, that runs on electricity or gasoline. Actually, a machine is anything that makes work easier to do. A machine helps you do work by transfering energy from one place to another, or from one form to another.

We use machines because they help us do things that we could not otherwise do. We use machines like bicycles, skateboards, and cars to make us go faster. Other machines make us stronger, like a bottle opener, which multiplies the force you apply, allowing you to get the bottle top off. Machines also let us put force exactly where we want it. For instance, a hammer allows you to put force exactly on the head of a nail, with more force than you could manage without the hammer. Also, machines let us do things that we could not do just ourselves.  For example, we can see in the dark with the help of a flashlight, or we can ride in the sky with a hang-glider.

Machines helping us do work
Machines help us do work. Can you spot the machines in these pictures?

In this lesson, you will learn about some simple machines and how they make work easier.  You will be able show mathematically how simple machines reduce the amount of work that we have to do in many everyday activities.  By the end of this lesson, you should be able to recognize simple machines in many of the objects and buildings all around you.