Question

A gun of mass 20kg fires a bullet of mass 0.1 kg and recoils with a velocity
of 1m/s. Calculate the velocity with which the bullet is fired. (2 m)​

Answer 1

Given:-

→Mass of the gun(M)=20kg

→Mass of the bullet(m)= 0.1kg

→Recoil velocity of the gun(V)=1m/s

To find:-

→Velocity with which bullet was fired(v)

Solution:-

By using Law of Conservation of momentum,we get:-

=>M(-V)+mv=0

=>v=MV/m

=>v=1×20/0.1

=>v=20/0.1

=>v=200m/s

Thus,the bullet was fired with a velocity of 200m/s.

Some Extra Information:-

Conservation of momentum:It is a fundamental law of physics which states momentum of a system will remain constant/conserved if no external forces are acting on the system.

Recoiling of gun:It is an application of Newton's 3rd law of motion i.e. "For every action,there is an equal and opposite reaction". It generally means,the backward velocity of the gun ,when one shoots a bullet. The recoil velocity is also a result of Conservation of momentum of the system.