Power of a body is defined as the rate at which the body can do the work.
(1) Dimension : [P] = [ML2T–3]
(2) Units : Watt or Joule/sec [S.I.]
Practical Units : Kilowatt (kW), Mega watt (MW) and Horse power (hp)
Relations between different units : 1 watt = 1 Joule/sec = 107 erg/sec
1hp = 746 Watt
(3) The slope of work time curve gives the instantaneous power. As P = dW/dt = tan θ