Question

a 15 gram gun fires a bullet a a muzzle velocuty of 600 m/s. What is the recoil velocity of the gun?

Answer 1

Given:

$m_{gun}=15\:\rm g$

$m_{bullet}=2\:\rm g$

$v_{bullet}=600\:\rm m/s$

The law of conservation of momentum says

$$m_{bullet}v_{bullet}=m_{gun}v_{gun}$$

Hence, the recoil speed of the gun

$$v_{gun}=\frac{m_{bullet}v_{bullet}}{m_{gun}}=\frac{2*600}{15}=80\:\rm m/s$$