Question

A 40 g bullet was fired from a gun of mass 2 kg. If speed of the bullet is 500 m/s, find the recoil speed of the gun?

Answer 1

Given the mass of the gun, M = 2 kg,
mass of the bullet, m = 0.4 kg
Speed of the bullet, v = 500 m/s.
Let the velocity of recoil of the gun = V
Using conservation of momentum, we get
Momentum after = momentum before
MV – mv = 0 (as initial momentum was zero)
or, MV = mv
or, 2*V = 500*0.4
or, V = 200/2 = 100 m/s