A bullet of mass 0.03 kg is fired from a rifle of mass 5 kg at a speed of 250 m/s. Before the bullet is fired, the initial momentum is zero.

Question

a) What is the momentum of the bullet just after it is fired?

b) What is the momentum of the rifle? (hint: the total momentum of the rifle and bullet must be zero)

c) What is the recoil velocity of the rifle?

Answer 1

a) The momentum of the bullet just after it is fired is 7.5 kg m/s.

b) The momentum of the rifle is -7.5 kg m/s.

c) The recoil velocity of the rifle is -0.03 m/s.