Q 11-04-031JEE MainAIEEE 2010Hard
The position-time graph of a body of mass $0.04$ kg is shown in the figure. The time between two consecutive impulses received by the body and the magnitude of each impulse is
Answer: (B) $2$ s, $8 \times 10^{-4}$ kg m/s
Concept. On an $x$–$t$ graph the slope is the velocity. A sharp corner means the velocity reverses suddenly: an impulse $m\Delta v=2mv$.
Step 1. Speed. The body moves $2$ cm in $2$ s each way: $v=1$ cm/s $=0.01$ m/s.
Step 2. Time between impulses. The corners come every $2$ s.
Step 3. Size of each impulse. $2mv=2\times0.04\times0.01=8\times10^{-4}$ kg m/s.
Answer. $2$ s, $8\times10^{-4}$ kg m/s (Option B).
Solution by Sreeraj P, M.Sc Physics
