If a boy of mass 40 kg runs up a staircase of 20 steps,... – Physics

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If a boy of mass 40 kg runs up a staircase of 20 steps, each 15 cm high, in 10 s, his power is (g=10 m/s^2):

A120 W

B1200 W

C60 W

D12 W

✓ Correct Answer: A — 120 W

Total height = 20 * 0.15 m = 3 m. Work = mgh = 40 * 10 * 3 = 1200 J. Power = 1200 / 10 = 120 W.

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