Question

A gun of mass 4 kg fire a bullet of 10 kg in forward direction calculate total intiao momentum and recoil velocity of gun

Answer 1

Initially velocity of gun and bullet is zero,
so initial momentum is zero.

And according to conservation of momentum,
initial momentum = final momentum
0 = m1 v1 - m2 v2

m1 & v2 are the mass and velocity of gun.
m2 & v2 are the mass and velocity of bullet.

4 v1 = 10 v2
v1 = 2.5 v2