Work, Power & Simple Machines

Energy

the ability to do work

Work

Exerts a force over a distance to move an object

Power

the rate at which work is done

Machine

A device that makes work easier

Compound machine

a device that combines two or more simple machines

Efficiency

compares the output work to the input work

Fulcrum

fixed point on a lever

Input force

the force you exert on a machine

Output force

the force exerted by a machine

Effort

the force required to do work

Units for Work

Joules

Units for Power

Watts

Force x Distance

Formula for Work

Work ÷ Time

Formula for Power

Lever

a simple machine that consists of a bar that pivots at a fixed point called a fulcrum

Incline Plane

a sloping surface, such as a ramp, that reduces the amount of force required to do work

Pulley

A simple machine that consists of a rope that fits into a groove in a wheel

Screw

a simple machine that consists of an inclined plane wrapped around a cylinder

Wedge

a simple machine that is an inclined plane that moves

Wheel and Axle

a simple machine consisting of a round disc and a long rod.