Question

A particle strikes elastically with another particle with velocity $V$ . After collision, it moves with half the velocity in the same direction. Find the velocity of the second particle if it is initially at rest.

• A. $\frac{3 V}{2}$
• B. $\frac{V}{2}$
• C. $V$
• D. none of these

Answer 1

Answer: (A)

We know that
$\left(\overset{ \rightarrow }{v_{2}} - \overset{ \rightarrow }{v_{1}}\right)=e\left(\overset{ \rightarrow }{u_{1}} - \overset{ \rightarrow }{u_{2}}\right) \, \, \, $
or $\left(\overset{ \rightarrow }{v_{2}} - \frac{v}{2}\right)=1\left(v - 0\right)$ (for an elastic collision $e=1$ )
or $v_{2}=\frac{3 V}{2}$