A body is allowed to fall freely under gravity from a height of 12 m. It loses of 25% of its energy when it first hits the ground. To what height will it rise after the first impact with the ground?
Correct answer: C. 9 m
- A. 3 m
- B. 6 m
- C. 9 m
- D. 10 m
Explanation
After the impact the 25% of energy is lost while 75% of its initial energy is left behind.P.E2 = 0.75P.E1mgh2= 0.75mgh1h2 = 0.75h1 = 0.75(12) = 9 m
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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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