Question

. A boy of mass 40 kg runs up a flight of 15 steps each
0.15 m high in 10 s. Find the work done and the power
developed by him. Take g = 10 m s-2)
(Ans. 900 J and 90 W)​

Answer 1

Answer:

Force of gravity on boy F= mg = 40 × 10 = 400N Total distance covered in 15 steps , S = 15 × 15cm = 225cm = 2.25m Work done by the boy in climbing = Force x distance moved in direction of force Work, W = F × S = 400 × 2.25 = 900J Power developed = work done/time taken = 900J/10s = 90W

Explanation:

Answer 2

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