Simple machines have few or no moving parts while complex machines are composed of two or more simple machines working together as a single mechanism. Both types of machines make it easier to perform a task.
Machines make work easier by:
- Changing the speed or distance of the force
- Increasing the magnitude of the acting force over the applied force
- Changing the direction of the applied force to that of the acting force
- Transferring the force from where it was applied to where it acts
Simple machines employ one or more of these methods to reduce the amount of effort required. There are six simple machines:
- Inclined plane
- Wheel and axle
Because both wedges and screws are modified inclined planes, they are not always included in lists of simple machines.
Complex machines, also called compound machines, combine multiple simple machines to enhance the reduction of effort that the simple machines could supply individually.