A body is dropped from 1000m height, if its potential energy is 8 x 10⁸ J. What will be its velocity on reaching the ground?
Correct answer: B. 141 ms-1
- A. 1410 ms-1
- B. 141 ms-1
- C. 1.41 ms-1
- D. 9800 ms-1
Explanation
Using v = √(2 g h) with g ≈ 10 m/s², v = √(2×10×1000) = √20000 ≈ 141 m/s. Thus, option B is correct.
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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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