Question

A man weighing 80 kg climbs a staircase carrying a 20 kg load.The staircase has 40 steps each of 25 cm height.If he takes 20 seconds to climb the work done is?

Answer 1

work done = Force × displacement
Force = weight = (80+20)kg × 10ms^(-2)= 1000 N
displacement s = 40×25 cm = 10 m
so work done
$w \: = force \: \times displacement$
$1000n \: \times 10m = {10}^{4} joule$