Power

Power:

Rate of doing work or  work done per unit time is called power of the machine or man.

It is a scalar quantity represented by a symbol P.

Power =work / time.

SI unit of power is watt.

1 watt is equals to 1 joules per second.

Higher units of power are 1 Kilowatt, 1 megawatt, 1 gigawatt.

Commercially power is measured in Horsepower.

1 horsepower is equal to 746 watt.

Power can be expressed in different way :

Power is equals to force x distance divided by time.
( when moving in body)

Power is equals to minus force x distance by time.
( when stopping a body)

Power is equal to force x velocity cos theta
( when pulling a body)

Power is equals to mX gX h/ time
( when lifting a body against gravity)

Power is equals to Force X velocity
( when moving with velocity