QUICK
Two balls collide inelastically. After the collision, the momentum of the system is 18 kg•m/s.


Before the collision, 1 ball had mass 3 kg and speed 1 m/s. What was the momentum of the second ball before the collision?


A: –6 kg•m/s

B: 15 kg•m/s

C: –15 kg•m/s

D: 6 kg•m/s