Question

a man of mass 20kg climbs a ladder in 20s. if the height of the ladder is 10m, how much power is used ?(g=10mper sec squre)

Answer 1

mgh/t

20*10*10/10
200watt

Answer 2

Power is defined at as work done per unit time.
Work done = Change in potential energy.
= mg(h2-h1)
= 20x10x(10-0)
= 2000J
Power = 2000/20
= 100 w