Q 11-04-010NEETNEET 2021Top questionEasy
A ball of mass $0.15$ kg is dropped from a height $10$ m, strikes the ground and rebounds to the same height. The magnitude of impulse imparted to the ball is ($g = 10\ \text{m/s}^2$) nearly :
Answer: (C) $4.2$ kg m/s
Concept. Impulse $=$ change in momentum; it rebounds with the same speed.
Step 1. Speed. $\sqrt{200} \approx 14.1$ m/s.
Step 2. Impulse. $0.15 \times 2 \times 14.1 \approx 4.2$ kg m/s.
Answer. $4.2$ kg m/s (Option C).
Solution by Sreeraj P, M.Sc Physics