Question

A machine gun fires n bullets per second and the mass of each bullet is m. If the speed of bullets is
v, then the force exerted on the machine gun is
(A) mng
(B) mnv
(C) mnvg
(D) mnv/g
Please explain with steps

Answer 1

Answer:

Force exerted on Machine Gun = mnv

so, Option (B) mnv is correct.

Explanation:

● Number of bullets fired per second = n

● initial velocity of Bullets = u = 0

● mass of each bullet = m

● final velocity of bullets (i,e given as speed of bullets) = v

We need to find the force exerted on the machine Gun

Calculating acceleration (a) of Bullets

→ a = Δ v / Δ t

→ a = ( v - u ) / 1

→ a = ( v - 0 )

→ a = v

therefore, magnitude of acceleration of bullets is equal to the magnitude of speed of bullets.

Calculating Force exerted (F) on the machine Gun

→ Force = mass × acceleration

→ F = ( m × n ) × v

( since n number of bullets are fired per second therefore, total mass will be equal to m times n )

→ F = m n v

Therefore,

Force exerted on the machine Gun is mnv.