Recoil of Gun | Recoil of Gun is an example of Law of conservation of linear momentum
Recoil of Gun is an example of Law of Conservation of Linear Momentum. Initially when the gun is not fired, the gun as well as the bullet inside it is at rest. So total momentum of system(Gun + Bullet) before firing is zero.
After firing, let the velocity of the bullet is 
M = mass of gun and m = mass of bullet
By the law of conservation of liner momentum,
Total momentum before firing the gun = Total momentum after firing the gun
The above expression is the recoil velocity of gun. From above expression we note that :
- The negative sign indicates that the recoil of gun is opposite to the velocity of bullet.
- Ratio
, indicates that the velocity of gun is less than the velocity of bullet.
Example :
A gun weighing 10 kg fires a bullet of 20g with a velocity 250 m/s. With what velocity does the gun recoil?
Solution :-
Here M = 10 kg, m = 2g = 0.02 kg, v = 250 m/s, V = ?
Applying the law of conservation of liner momentum,
Total momentum before firing the gun = Total momentum after firing the gun
0 = MV + mv
V = – 0.5 m/s