Question

A loaded spring gun of mass M fires a shot of mass m with a velocity v at an angle of elevation $\theta$. The gun is initially at rest on a horizontal frictionless surface. After firing, the centre of mass of the gun-shot system

• A. moves with a velocity $\frac{vm}{M}$ in the horizontal direction.
• B. moves with velocity $\frac{vmcos\theta }{M}$ in the horizontal direction.
• C. remains at rest in the horizontal direction.
• D. moves with a velocity $\frac{v(M-m)}{(M+m)}$ in the horizontal direction.

Answer 1

The correct option is C

remains at rest in the horizontal direction.

Since there is not external force acting on the gun-shot system in the horizontal direction, the centre of mass of the system continues to remain at rest. Hence, the correct choice is (c).