Question

When a bullet of mass 50 g is fired from a gun of mass 10 kg, the gun recoils with a velocity 2 m/s. Find the muzzle velocity of the bullet.

Answer 1

Since no external force acts on the rifle-bullet system, the momentum of the system will remain conserved.
MV = mv
$\Rightarrow 10\times 2=0.050\times v$
$\Rightarrow v=400m/s$