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 burst?
A) 45 N
B) 5.6 N
C) 16 N
D) 2.0 N
E) 23 N

Question

Quizplus · Accepted Answer

The average recoil force can be calculated using the change in momentum over time. The total momentum change is the mass of all bullets times their speed: (8 bullets * 0.0075 kg/bullet * 300 m/s). The time is 0.40 s. The average force is the total momentum change divided by time, which gives 45 N.

An Assault Rifle Fires an Eight-Shot Burst in 0