A gun of mass 1000 kg fires a projectile of mass 1 kg with a horizontal velocity of 100 m/s. The velocity of recoil of the gun in the horizontal direction is :

0.1 m/s

\(\Rightarrow P_i = P_f\)

\(\Rightarrow m_1u_1 + m_2u_2 = m_1v_1 + m_2v_2\)

\(\Rightarrow (1*0) + (1000*0) = (1*100) (1000 v)\)

\(\Rightarrow 0 = (1*100) (1000 v)\)

\(\Rightarrow 1000 v = -100\)

\(\Rightarrow v = - 0.1 \text{m/s}\)