Question

A man M1 of mass 80kg rubs up a stair case in 15s. another man M2 also of mass 80 kg runs up a same staircase in 20 s. The ratio of power developed by then will be

Answer 1

power=work/time
p1=work by against gravity/time =80gh÷15
p2=80gh÷20
hence p1÷p2=20÷15=4/3