A mass ' $m$ ' moves with a velocity $v$ and collides inelastically with another identical mass. After collision the $1^{\text {st }}$ mass moves with velocity $v / \sqrt{3}$ in a direction perpendicular to the initial direction of motion. Find the speed of the $2^{\text {nd }}$ mass after collision

• A

  v
• B

  $\sqrt{3} v$
• Correct answer
  C

  $2 v / \sqrt{3}$
• D

  $v / \sqrt{3}$

Solution

$m v=m v_1 \cos \theta$ $0=\frac{m v}{\sqrt{3}}-m v_1 \sin \theta$ $\therefore v_1=\frac{2}{\sqrt{3}} v$

Hence, the correct answer is option: 'C'.