Q. A loded spring gun of mass $M$ fires a shot of mass $m$ with a velocity $v$ at an angle of elevation $\theta$. The gun was initially at rest on a horizontal frictionless surface. After firing, the centre of mass of gun-shot system
A) Moves with a velocity $\frac{mv}{M}$
B) Moves with a velocity $\frac{mv}{M\cos\theta}$ in the horizontal direction
C) Remain at rest
D) Moves with velocity $\frac{(M - m)v}{(M + m)}$ in the horizontal direction
Explanation
(c) Since gun-shot system is an isolated closed system, its centre of mass must remain at rest.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.