A gun of mass 10 kg fires 4 bullets per second. The mass of each bullet is 20 g and the velocity of the bullet when it leaves the gun is $300{\text{\hspace{0.17em}ms}}^{-1}.$ The force required to hold the gun while firing is

Mass of gun =10 kg

Mass of bullet = $\text{20}\times {\text{10}}^{-\text{3}}\text{kg}$

Velocity of bullet $=300\text{\hspace{0.17em}m/s}$

No. Of bullets fired = 4

Velocity of gun$\text{=}-\text{20}\times {\text{10}}^{-\text{3}}\text{kg}\times \text{4}\times \text{300/10}$

velocity of gun $=-\frac{12}{5}\text{\hspace{0.17em}m/s}$

$\text{F}=\text{ma}=\text{m}\left(\frac{\text{v}-\text{u}}{\text{t}}\right)$ 

Mass =10kg

Initial velocity ,u = 0, t =1 sec

Final velocity,

 $\text{v}=\frac{12}{5}$

Therefore,

 $\text{F}=10\times \frac{12}{5}$

F = 24N