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Q: A boy of 50 kg mass climbs 40 stairs in 10 seconds. If the height of each stair is 15cm, then calculate his power.(g= 10ms-² )
  • A. 337.5W
  • B. 300J
  • C. 300W
  • D. 300ms
Correct Answer: Option C - Given, mass of boy, m = 50 kg h = 40 x15 = 600 cm = 6.0 m t = 10 s, g = 10 m/s² PE = mgh = 50 x 10 x 6 = 3000 J Power = PE / time = 3000/ 10 = 300 W
C. Given, mass of boy, m = 50 kg h = 40 x15 = 600 cm = 6.0 m t = 10 s, g = 10 m/s² PE = mgh = 50 x 10 x 6 = 3000 J Power = PE / time = 3000/ 10 = 300 W

Explanations:

Given, mass of boy, m = 50 kg h = 40 x15 = 600 cm = 6.0 m t = 10 s, g = 10 m/s² PE = mgh = 50 x 10 x 6 = 3000 J Power = PE / time = 3000/ 10 = 300 W