A shell of mass 200 gm is ejected from a gun of mass 4 kg by an explosion that generates 1.05 kJ of energy. The initial velocity of the shell is : 

100 m/s

Let the initial velocity of the shell be v, then velocity of gun = \(\frac{0.2}{4}v\) [Conservation of Linear Momentum]

∴ 1.05 × 103 = \(\frac{1}{2} × 0.2 × v^2 + \frac{1}{2} × 4 × (\frac{0.2}{4}v)^2\)

⇒ v = 100 m/s