Q 11-04-106JEE MainJEE Main 2023 (30 Jan, Shift 2)Easy
A machine gun of mass $10\ \text{kg}$ fires $20\ \text{g}$ bullets at the rate of $180$ bullets per minute with a speed of $100\ \text{m s}^{-1}$ each. The recoil velocity of the gun is
Answer: (D) $0.6\ \text{m s}^{-1}$
The gun fires $3$ bullets per second. Momentum given to the bullets in one second $=3\times0.02\times100=6\ \text{kg m s}^{-1}$.
The gun gets an equal and opposite momentum: $v=\dfrac{6}{10}=0.6\ \text{m s}^{-1}$.
Solution by Sreeraj P, M.Sc Physics