A machine gun has a mass of 20 kg . It fire 20 gram bullets at the rate of 300 bullets per second at a speed of `250 m//s` . What force must be applied on the gun to keep it in position ?

Explanation

Here , `M =20 kg `
` m=20 g = 20 xx 10^(-3) kg , n = 300 , upsilon = 250 m//s `
Force requird to hold the gun in position F = rate of change of momentum of bullets
= n m v
`F = 300 xx 20 10^(-3) xx 250 = 1500 N ` .