The velocity and momentum of a moving body are 10,000 cm s⁻¹ and 10,000 g cm s⁻¹ respectively. The K.E will be
Correct answer: D. 5 x 10⁰ J
- A. 5 x 10⁷ J
- B. 5 x 10⁻² J
- C. 5 x 10⁸ J
- D. 5 x 10⁰ J
Explanation
Using KE = ½ p v with SI units: convert v = 10000 cm/s = 100 m/s, p = 10000 g·cm/s = 0.1 kg·m/s (better: p in SI = 10,000 g·cm/s = 0.1 kg·m/s), then KE = ½ p v = 0.5×0.1×100 = 5 J.Option D corresponds to 5 J (5×100 J).
Last updated
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.
Practise Work and Energy
748 free Work and Energy MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.