Question

A machine gun fires 20 bullets per second into a target.each bullet weighs 150 grams ad has a speed of 800 m/s.find the force necessary to hold the gun in position

Answer 1

Let us say each bullet takes about 1/20 th of a second to come out of the barrel of the gun.  Each bullet then accelerates from rest to a speed of 800 meters in a time duration of 1/20 = 0.05 sec.

Acceleration of a bullet = a = (800 - 0 ) / 0.05 sec = 16000 m /sec²
Force necessary to give the bullet this acceleration = m a
           = (150 /1000) kg * 16000 m/sec²
           = 2400 Newtons

The bullets exert the same amount of force on the machine gun as the machine gun exerted on the bullets.

Force necessary to hold the gun = recoil force of gun = 2400 Newtons

Answer 2

Answer:

2400 newtons is the answer