A vehicle is traveling west with a momentum of 1,800 kg•m/s. A second vehicle is traveling east with a momentum of 1,200 kg•m/s. The vehicles collide.

Question

What is the total momentum of the system after the two cars collide?
A. 600 kg•m/s westward
B. 1,200 kg•m/s westward
C. 1,800 kg•m/s westward
D. 3,000 kg•m/s westward

I think the answer is A.

Answer 1

Momentum before = momentum after.
M1*V1 + M2*V2 = -1800 + 1200 = -600 kg*m/s. = 600 kg*m/s Westward.