Question

12. A machine gun fires n bullets per second and the mass of each bullet is m. If v is the speed of each bullet, then the
average force exerted on the machine gun is
(1) mng
(2) mnv
(3) mnvg
(4) (mnv)/g​

Answer 1

Answer:

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