Question

A bullet of mass $50gram$ is fired from a $5kg$ gun with a velocity of $1km/s$. The speed of recoil of the gun is

• A. $5m/s$
• B. $1m/s$
• C. $0.5m/s$
• D. $10m/s$

Answer 1

The correct option is D $10m/s$

Since There is no external Force acting, we can apply momentum conservation.

According to conservation of momentum:

$m_B{v}_B+m_G{v}_G=0\Rightarrow v_G=-\frac{m_B{v}_B}{m_G}$

$v_G=\frac{-50\times {10}^{-3}\times {10}^3}{5}=-10m/s$