Question

it takes 20 s for a girl A to climb up the stairs while girl B takes 15 s for the same job. compare : (i) the work done and (ii) the power spent by then.

Answer 1

Answer:

i) As the height is the same for both girls A and B, work done is same (irrespective of time)

Therefore, work done by A : Work done by B = 1:1

ii) Power = Work done/Time taken = Energy/time = (Energy/Time1)/(Energy/Time2)

=Time1/Time2 = 15/20 = 3/4 = 3:4

Answer: i) 1:1

ii) 3:4

Answer 2

Ans = 3:4

Power = work done / Time taken = Energy / Time

Power of A/Power of B=

Energy/ T1/ Energy/T2

= 1/ T1* T2/1 = 15/20=3/4=3:4

Hope you understand :)