Question

A machine gun has a mass 5kg. It fires 50gram bullets at the rate of 30 bullets per minute at a speed of 400ms. What force is required to keep the gun in position

Answer 1

Here,Mass Of Machine Gun(m)= 20kg

Mass of each Bullet, (M)=35g=0.035kg

Velocity Of Bullet(v)=400m/s

No.Of Bullets/sec=400/60=20/3

Force required = rate of change of linear momentum of bullets=n(mv)/t

=20/3×(0.035×400)/1=93.3N

Answer 2

Answer:

10 Newton

Explanation:

F = Force

t = Time taken = 60 seconds

u = Initial velocity = 0

v = Final velocity = 400 m/s

Number of bullets = 30

m = Mass of bullet = 50 g

Impulse

$Ft=m(v-u)\\\Rightarrow F=\frac{m(v-u)}{t}\\\Rightarrow F=\frac{50\times 10^{-3}\times (400-0)}{60}\\\Rightarrow F=\frac{1}{3}$

Force required to hold the gun for 1 bullet

For 30 bullets

$F=\frac{1}{3}\times 30\\\Rightarrow F=10\ N$

Force required to keep the gun in place is 10 Newton