Power

The rate of doing work is called power. It is a scalar quantity. Its SI unit is Watt (W). Another common unit of a power is horsepower. Horsepower is related to watt as:

1 horsepower = 746 W = 750 W approximately.

Power =

1 kilowatt (KW) = 1000 watt

1 megawatt (MW) = 1000000 watt

1 horsepower (HP) = 750 watt (approx.)

The power is one watt when one joule of work is done in one second.

Relation between Work, Energy and Power

Work, energy and power are interrelated terms. Actually, the capacity to do work is a power which comes from energy. When a person does a work then he loses some amount of energy. We get energy from food. Our body stores chemical energy and transforms it into muscular energy. We use that muscular energy to do work.

The rate of doing work is power. If we work faster then power is increased. If higher energy is applied to do work then work done becomes faster and power will also get increased. So, work, energy and power are interrelated terms.