Discuss the practical applications of the law of conservation of momentum
Answers
A system of gun and a bullet.Before firing the gun, both the gun and the bullet are at rest,so the total momentum of the system is zero.As the gun is fired, bullet shoots out of the gun and acquires momentum.To conserve momentum of the system,the gun recoils.According to the law of conservation of momentum,the total momentum of the gun and the bullet will be zero after the gun is fired.Let m be the mass of the bullet and v be the velocity on firing the gun; M be the mass of the gun and V be the velocity with which it recoils.Thus the total momentum of the gun and the bullet after the gun is fired will be:
Total momentum of gun and bullet after the gun is fired = M v + m v ….(1)
According to the conservation of momentum law:
Total momentum of gun and bullet after the gun is fired =Total momentum of gun and bullet before the gun is fired
Therefore we get:
M V +mv = 0
or M V = -m v
V=-mv/M
Hence proved