Q. A particle of mass $m$ moving with velocity $u$ makes an elastic one dimensional collision with a stationary particle of mass $m$. They are in contact for a very short time $T$. Their force of interaction increases from zero to $F_{0}$ linearly in time $T/2$, and decreases linearly to zero in further time $T/2$. The magnitude of $F_{0}$ is
A) $mu/T$
B) $2mu/T$
C) $mu/2T$
D) None of these
Explanation
(b) In one dimensional elastic collision when two particles of same mass colloid with each other their velocity are interchange
$i.e.$ change in momentum of particle $|0 - mu| = mu$
But impulse = change in momentum
$\Rightarrow \frac{1}{2} \times F_{0} \times T = mu$
$\therefore F_{0} = \frac{2mu}{T}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.