Rifle Recoil A(n) 4.5 kg rifle fires a 34.3 g bullet at 397.2 m/s. What is the magnitude of the recoil momentum of the rifle in mks units?

Question

Rifle Recoil

A(n) 4.5 kg rifle fires a 34.3 g bullet at 397.2 m/s.

What is the magnitude of the recoil momentum of the rifle in mks units?

Answer 1

Given Mass of Rifle = 4.5Kg ( not needed to solve this problem)

Mass of bullet = 34.3 /1000 Kg

speed of bullet = 397.2 m/s

Using law of conservation of momentum.

As system is at rest before bullet is fired ( total momentum is zero)

Momentum of rifle + Momentum of bullet = 0

Momentum of rifle = - Momentum of bullet = - mv ( where m = mass of bullet and v= speed of bullet)

= - (34.3/1000) *397.2 Kgm/s= - 13.62 Kgm/s Negative sign means opposite to the direction of bullet