Question

A gun fires a bullet of mass 50 g with a velocity of 30 m s${}^{-1}$. Because of this gun is pushed back with a velocity of 1 m s${}^{-1}$. Mass of the gun is :

• A. 3.5 kg
• B. 3 kg
• C. 1.5 kg
• D. 2 kg

Answer 1

The correct option is C 1.5 kg

Initial momentum $=$
Final momentum $=m_g{v}_g+m_b{v}_b$
$(0.05\times 30)+(m_g\times 1)=0$
$m_g=1.5kg$