Question

A rnachine gun of l5 kg fires 0.02 kg bullets at the rate of l0 per second with a speed of
300 m/s. Calculate the force required to hold the gun in position.

Answer 1

Mass of each bullet=m

Speedf each bullet=v

Number of bulllets fired per second=n

There fore exerted on the machine gun is,

f=mnv

The forece is directly proportional to rate of change of momentum

Therefore Per second the bullet fires,

f=mv

Since accelartaion ,a=v-u/t

u=0

t=1

a-v=0

Therefore Force by one bullet is mv

and force by n bullets is mnv

now solve