Question

A boy of mass 40 kg runs up a flight of 50 steps, each of 10 cm high in 5 seconds. Find the power developed by the boy?

Answer 1

Work Done can be calculated as

W = F * d
= m * g * d
= 40 * 10 * 50 *0.1
= 2000
= 2 KJ.
thus 2 KJ of work is done by the boy
Power Dissipated can be calculated as
P = W / t
= 2/5
= 0.4 K Watt = 400 Watt
thus power dissipated is 400 Watt.