A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg. The velocity of 18 kg mass is 6 m s⁻¹. The K.E of other mass is
Correct answer: B. 486 J
- A. 324 J
- B. 486 J
- C. 256 J
- D. 524 J
Explanation
Momentum conservation: 0 = 18×6 + 12 v ⇒ v = −9 m/s. KE of 12 kg = ½×12×9² = 486 J. So 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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