Question:
A bullet of ' $4 \mathrm{~g}^{\prime}$ mass is fired from a gun of mass $4 \mathrm{~kg}$. If the bullet moves with the muzzle speed of $50 \mathrm{~ms}^{-1}$, the impulse imparted to the gun and velocity of recoil of gun are:
Correct Option: , 2
Solution:
By momentum conservation
$4 \times 10^{-3}(50-v)-4 v=0$
$\mathrm{v}=\frac{4 \times 10^{-3} \times 50}{4+4 \times 10^{-3}} \approx 0.05 \mathrm{~ms}^{-1}$
Impulse $\mathrm{J}=\mathrm{mv}=4 \times .05=0.2 \mathrm{kgms}^{-1}$