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Question
A girl of mass 50 kg runs up a flight of 40 steps in 20 seconds. If each step in 20 cm high, calculate the power developed by the girl. (g= 10 ms-2).
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Solution
Given, mass = 50kg
Total height traveled = 40 x 20 cm = 800 cm = 8 m
g = 10ms-2
time taken = 20s
work done = mgh = 50 x 10 x 8 = 4000 J
power = `"work done"/"time taken" = 4000/20 = 200 "watt"`
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