Question

Why does a gun recoil when a shot is fired from it?

Answer 1

1. When a gun is fired, the bullet goes out due to the force applied to it through the trigger (this is action).
2. The gun recoils backward due to the reaction acting on it in the opposite direction.
3. This gives a backward jerk to the shoulder of the gunman.
4. The change in the momentum of the bullet is equal and opposite to that of the gun. Initially, both the shot and the gun are at rest. So, the momentum produced in the gun is equal to and opposite to that produced in the bullet.
5. Thus, $MassofbulletxSpeedofthebullet=MassofthegunxSpeedofthegun$
6. Since, the mass of the gun is much greater than that of the bullet, the speed of the gun is very small as compared to that of the bullet.
7. Therefore, the gun moves backward only by a small distance during recoil.