Question

A machine gun fires a bullet of mass 40 g with a
velocity 1200 m/s. The man holding it can exert
maximum force of 144 N on the gun. The number
of bullets he can fire per second will be

Answer 1

Mass of each bullet = 40 g = .040 kg

Velocity of each bullet = 1200 m/s

Let 'n' be the number of bullets fired per second. Then, change in momentum of the bullets coming out per second is,

= force on the man

=> n (0.040)(1200) = 144

=> n = 3