Question

It takes 20s for A to climb up the stairs, while B does the same in 15s.
Compare (i) the W.D by A&B (ii) the power developed by A&B.

Answer 1

Answer:

Let h be the height of staircase climbed by A and B. Let mA is weight of A and mB is weight of B.

 

Workdone by A to climb the Staircase, WA = mA×g×h Joules

Workdone by B to climb the Staircase WB = mB×g×h Joules

 

Hence the ratio WA/WB = mA / mB

 

Power developed by A,  PA = (mA×g×h)/20 watts

Power developed by B,  PB = (mB×g×h)/15 watts

 

Power ratio PA/PB = (15mA)/(20mB) = (3mA)/(4mB)