Question

A machine gun has a mass of 5kg.It fires 50 gram bullets at the rate of 30 bullets per minute at a speed of400m/s.What force is required to keep the gun in position.

Answer 1

application of Newton's second law

Answer 2

Answer: The correct answer is 10 N.

Explanation:

Calculate the change in the momentum for the 30 bullets by converting the mass of the bullet into kilogram and multiply it with velocity of the bullet.

$Change in momentum= 50\times 10^{-3}\times 30\times 400$

The expression for the force in terms of the change in momentum is as follows by using Newton's second law;

$F=\frac{Changeinmomentuminbullets}{Time\ taken}$

It is given in the problem that A machine gun has a mass of 5 kg.It fires 50 gram bullets at the rate of 30 bullets per minute at a speed of 400 m/s.

Put t= 1 min= 60 s and $Change in momentum= 50\times 10^{-3}\times 30\times 400$.

$F=\frac{50\times 10^{-3}\times 30\times400}{60}$

$F=10 N$

Therefore, the force required to keep the gun in position is 10 N.