A machine is a tool that helps us do work more easily. Some machines are simple, and some are made of many parts working together.
Simple machines
A simple machine has few or no moving parts. It makes work easier on its own. There are common types such as the lever, pulley, wheel and axle, inclined plane (ramp), wedge and screw.
Key idea
A simple machine has few parts. A complex machine is made of two or more simple machines working together.
Complex machines
A complex machine is made by joining two or more simple machines. It can do bigger or harder jobs. A bicycle uses wheels, levers and a screw. Scissors use levers and wedges (the sharp blades). Because the simple machines work together, a complex machine can do a job that one simple machine cannot do alone.
Example
A wheelbarrow is a complex machine. It uses a lever (the handles) and a wheel and axle together to carry heavy loads.
Remember
- Simple machine = few parts, works on its own.
- Complex machine = two or more simple machines joined together.