1) A machine gun has a mass 5 kg. It fires 50 gram bullets at the rate of 30 bullets per minute at a speed of 400 m/s. What force is required to keep the gun in position? A) 10 N B) 5 N C) 15 N D) 30 N Answer: Option AExplanation:Force required = $\frac{Change in momentum}{time taken}$ = $\frac{(50\times10^{-3}\times30\times400-(5\times0)}{60}$ = 10 N
