How Levers Work

Simple machine :  a device with few parts that makes it easier to do work.
Effort force :  the force applied to do a machine.
Resistance force :  the force that a machine acts against.
Lever : a simple machine made of a rigid bar on a pivot point.
Fulcrum:  the pivot point of alever.
Mechanical advatage: The number of times a mchine multiplies the force applied.
Pulley :  a grooved wheel that turns by the action of arope in the groove.
Wheel and axle : a simple machine made of a handle or axis attached to the center of a wheel.

Energy and Work

Potentional energy :  the energy stored in an object or material.
Gravitational potentional energy:  the potentional energy of an object located above the ground.
Kinetic energy:  the energy of amoving object.
Work :  force applied to an object times the distance the object moves.