Question

A gun fires a bullet of mass 60 g with a velocity of $30m{s}^{-1}$. Because of this, the gun is pushed back with a velocity of 1 m/s. Mass of the gun is:

• A. 3.6 kg
• B. 30 kg
• C. 1.8 kg
• D. 20 kg

Answer 1

The correct option is C 1.8 kg

Let $M=$ mass of gun , $u=$ velocity of gun, $m=$ mass of bullet and $v=$ velocity of bullet.

By conservation of momentum, $Mu=mv$ or $M=\frac{mv}{u}=\frac{\left(60/1000\right)\times 30}{1}=1.8$ kg