Two billiard balls, each with a mass of 0.17 kg, collide with each other on a
pool table. Before the collision, one ball is moving south at 2.8 m/s and the
other ball is moving north at 1.6 m/s. What is the momentum of this system
after the collision?
A. 0.60 kg-m/s south
B. 0.20 kg-m/s south
C. 0.20 kg.m/s north
D. 0.60 kg.m/s north