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 :
\( 2.5 \, \text{m/ s}^{} \)
\( 1.5 \, \text{m/ s}^{} \)
\( 0.6 \, \text{m/ s}^{} \)
\( 0.02 \, \text{m/ s}^{} \)