Question

A man of 60kg runs up a flight of 20 steps in 20 seconds if each step is 20cm high calculate power

Answer 1

Each step = 20cm

30 steps = 30×20= 600 cm = 6 m

now, power = W/Time

for work to be done we need force × displacement

force= mg

therefore W= mgh

= 60 × 9.8 × 6

= 3528 J

power = W/T

= 3528 ÷ 15

= 235 watt. ans..