Work and simple machines

Work

A force acting through distance
Work= force x distance

A tool that make work easier by changing the size or direction of the input force.

Machine

The six simple machines

Inclined plane - slanted surface
Wedge - inclined surface that moves
Screw - inclined plane with a bar wrapped around it
Lever - rigid bar that moves about a fixed point, called a fulcrum.
Pulley - rope, chain, or belt warped around a grooved wheel
Wheel and axle - two circular objects of different sizes; the force applied to the wheel is transferred to the axle

Screw.

Pulley

Inclined plane

Wheel and axle

Wedge

Lever