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Q: A boy of 50 kg mass climbs 43 stairs in 10 seconds. If the height of each stair is 15cm then find its power ?
  • A. 337.5W
  • B. 325.5J
  • C. 322.5W
  • D. 322.5ms
Correct Answer: Option C - Given, mass of boy, m = 50 kg h = 43 x15 = 645 cm = 6.45 m t = 10 s, g = 10 m/s² PE = mgh = 50 x 10 x 6.45 = 3225 J Power of the boy = PE / time = 3225 / 10 = 322.5 W
C. Given, mass of boy, m = 50 kg h = 43 x15 = 645 cm = 6.45 m t = 10 s, g = 10 m/s² PE = mgh = 50 x 10 x 6.45 = 3225 J Power of the boy = PE / time = 3225 / 10 = 322.5 W

Explanations:

Given, mass of boy, m = 50 kg h = 43 x15 = 645 cm = 6.45 m t = 10 s, g = 10 m/s² PE = mgh = 50 x 10 x 6.45 = 3225 J Power of the boy = PE / time = 3225 / 10 = 322.5 W