A particle of mass m moving with velocity

Your Ultimate Guide to JEE & NEET Question Solutions

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

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

In elastic one dimensional collision particle rebounds with same speed in opposite direction

i.e. change in momentum $ = 2mu$

But Impulse $ = F \times T = $ Change in momentum

$⇒$ ${F_0} \times T = 2mu$ $⇒$ ${F_0} = \frac{{2mu}}{T}$