Question

A boy weighing $350N$ nuns up a Bight of 30 steps, each $20cm$ high in $1$ minute. Calculate:
(i) the weak done and
(ii) power spent.

Answer 1

Total distance covered in 30 steps, $S=30\times 20cm=600cm=6m$
Work done by the boy in climbing $=$ Force $\times$ distance moved in direction of force
Work, $W=F\times S=350\times 6=2100J$
Power developed$=\frac{workdone}{timetaken}=\frac{2100J}{60s}=35W$