Question

A particle of mass ${}^{\prime }{m}^{\prime }$ and ${}^{\prime }{\overrightarrow{v}}^{\prime }$ collides oblique elastically with a stationary particle of mass ${}^{\prime }{m}^{\prime }$. The angle between the velocity vectors of the two particles after the collision is

• A. ${45}^{\circ }$
• B. ${30}^{\circ }$
• C. ${90}^{\circ }$
• D. None of these

Answer 1

Answer: (C)

${90}^{\circ }$

Collision is elastic hence velocities along the line of impact will be exchanged. Velocity of particle along the line of impact $V=v\cos \theta$

velocity of disc $=\frac{v\sqrt{3}}{2}$ so the particle will move perpendicularly.

So the correct option is $\left(C\right)$