Question

a man whose weight is 500 N moves up 15 steps each of height 15cm in 40 seconds of time calculate the power used in climbing those staris

Answer 1

we know that : 
 P= mgh/t
h = 15 / 100 * 40 
⇒ 6m 
here W = 500N 
here t = 40 seconds 
here g = 10
now using the formula P = mgh / t 
⇒$\frac{ 500 * 10 * 6}{40}$
⇒$\frac{30000}{40}$
⇒ 750 watt 
∴ the power used by the person to climb the steps = 750 watt