Question

12. An old man and a young boy both of mass 50 kg climb up the same height. While the old man climbs
up in 25 seconds, the boy climbs up in 15 seconds. Calculate the ratio of (i) the work done by them,
and (ii) their power.​

Answer 1

Explanation:

Work done=Force*distance

Force=mass*acceleration

Work done=mass*acceleration*distance

mass of old man=50kg

mass of young boy=50kg

taking acceleration due to gravity 10m/s²

ratio of work done=work done of old man/work done of young boy

=50*10*d/50*10*d

=1

hence ratio of work done is 1

ii) ratio of power = power of old man / power of young boy

power=work done/time

ratio of power=(500d/25)/(500d/15)

=3/5. or 3:5