Question

An assault rifle fires an eight-shot burst in 0.40 s. Each bullet has a mass of 7.5 g and a speed of 300 m/s as it leaves the gun. What is the average recoil force on the gun during that 0.40 s burst?

Answer 1

The average recoil force on the gun during that 0.40 s burst is 45 N.

Step-by-step explanation:

Mass of each bullet, m = 7.5 g = 0.0075 kg

Speed of the bullet, v = 300 m/s

Time, t = 0.4 s

The change in momentum of an object is equal to impulse delivered. So,

`F* t=mv\\\\F=(mv)/(t)`

For 8 shot burst, average recoil force on the gun is :

`F=(8mv)/(t)\\\\F=(7.5)/(1000)\cdot(300)/(0.4)\cdot8\\\\F=45\ N`

So, the average recoil force on the gun during that 0.40 s burst is 45 N.