A particle of mass m moving with a velocit

Your Ultimate Guide to JEE & NEET Question Solutions

A particle of mass m moving with a velocity $u$ makes an elastic one dimensional collision with a stationary particle of mass $m$ establishing a contact with it for extremely small time $T$. Their force of contact increases from zero to $F_0$ linearly in time $\frac{T}{4}$, remains constant for a further time $\frac{T}{2}$ and decreases linearly from  $F_0$  to zero in further time $\frac{T}{4}$ as shown. The magnitude possessed by $F_0$  is

A

$\frac{{mu}}{T}$

B

$\frac{{2mu}}{T}$

C

$\frac{{4mu}}{{3T}}$

D

$\frac{{3mu}}{{4T}}$

A particle of mass m moving with a velocity $u$ makes an elastic one dimensional collision with a stationary particle of mass $m$ establishing a contact with it for extremely small time $T$. Their force of contact increases from zero to $F_0$ linearly in time $\frac{T}{4}$, remains constant for a further time $\frac{T}{2}$ and decreases linearly from  $F_0$  to zero in further time $\frac{T}{4}$ as shown. The magnitude possessed by $F_0$  is

Change in momentum = Impulse
= Area under force-time graph
 $mv = $Area of trapezium
$⇒$  $mv = \frac{1}{2}\left( {T + \frac{T}{2}} \right)\;{F_0}$
$⇒$  $mv = \frac{{3T}}{4}{F_0}$ $⇒$ ${F_0} = \frac{{4mu}}{{3T}}$