### The amount of work done in a certain amount of time?

The amount of work done in a certain amount of time is the power. Power is measured in watts, and is defined as joules per second. Work is a mechanical form of energy. Dimensionally, it is Force*Distance. Typical units are ft-lb or watt-seconds. Power is the rate of work, dimensionally Force*Distance/Time. Typical units could be ft-lb/hour, or watt.

### In physics what is power and efficiency?

Power(P) is the amount of Work(W) done in a given amount of time(t). Efficiency(e) is a measure of how effective a machine is. This is done by taking the ratio of output work(Wo) and dividing that by the work input(Wi). e=Wo/Wi X 100 Another way of determining efficiency is... e=AMA/IMA X 100 (AMA=Actual Mechanical Advantage) (IMA=Ideal Mechanical Advantage)