A body builder lifts a 250 kg block from the ground to a height of 2 m in 2.5 s. The average power generated is: (Take g=10 m/s2)
Correct answer: D. 2000 watt
- A. 500 watt
- B. 1000 watt
- C. 1250 watt
- D. 2000 watt
Explanation
Power = work done / time Weight of the block = mg = 250 x 10 = 2500 N Work done = F x d = 2500 x 2 = 5000 J Power = 5000 / 2.5 = 2000 W
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About Work and Energy
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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