If the momentum of an object is increased twice, then what will be the kinetic energy?
Correct answer: C. Four times
- A. Twice
- B. Thrice
- C. Four times
- D. Sixteen times
Explanation
For a fixed mass, kinetic energy is K = p²/(2m), so it depends on the square of momentum. If momentum becomes 2p, then K' = (2p)²/(2m) = 4p²/(2m) = 4K, so the kinetic energy becomes four times its original value. The common mistake is choosing twice by treating kinetic energy as directly proportional to momentum.
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About Kinetic Energy
Kinetic energy is the energy of motion, given for a nonrelativistic object by K = ½mv², so it depends on mass and the square of speed. Questions connect kinetic energy with work through the work energy theorem, calculate changes in kinetic energy, and distinguish it from momentum and potential energy.
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