Why the recoil velocity of a gun is much less than the velocity of the bullet? Explain by using the principle of conservation of linear momentum

Answer 1

The recoil velocity of a gun is much less than the velocity of the bullet due to the principle of conservation of linear momentum.

According to the conservation of linear momentum, the total linear momentum of a system remains constant if no external forces act on it. In the case of a gun firing a bullet, the system includes both the gun and the bullet.

Before firing, the gun and the bullet are at rest, so the initial total linear momentum of the system is zero. When the trigger is pulled, the gunpowder inside the gun ignites, generating a high-pressure gas that pushes the bullet forward out of the barrel. The force exerted on the bullet in one direction creates an equal and opposite force, i.e., recoil, on the gun in the opposite direction.

As per the principle of conservation of linear momentum, the total momentum of the system must remain zero after the gun is fired. This means that the momentum of the bullet must be equal in magnitude but opposite in direction to the momentum of the gun.

Since the mass of the bullet is significantly smaller than the mass of the gun, the bullet must have a high velocity for its momentum to balance out the momentum of the gun. This is why the velocity of the bullet is much higher than the recoil velocity of the gun.

In simpler terms, the bullet gains a high velocity due to its small mass, while the gun experiences a lower velocity because of its larger mass. The momentum gained by the bullet is equal and opposite to the momentum gained by the gun, satisfying the conservation of linear momentum.