A machine gun is mounted on a 2000 kg vehicle on a horizontal smooth road (friction negligible). The gun fires 10 bullets per sec with a velocity of 500 m/s. If the mass of each bullet be 10 g, what is the acceleration produced in the vehicle?

Force acting on the vehicle = rate of change of momentum=$\frac{mnv}{t}$

acceleration of the vehicle:

$a=\frac{mnv}{M}$

$where, m = mass of each bullet, n= no of bullets per sec, v = velocity of each bullet \mathrm{an}d M = mass of the vehicle$

$a=\frac{10\times {10}^{-3}\times 10\times 500}{2000}=\frac{5}{200}=2.5 cm/s^2$