Question

Two cars collide. The total momentum in the system before the collision is 2,000 kg*m/s. What is the total momentum in the system after the collision?

Answer 1

Answer: Before the collision, one car had velocity v and the other zero, so the center of mass of the system was also v/2 before the collision. The total momentum is the total mass times the velocity of the center of mass, so the total momentum, before and after, is (2m)(v/2) = mv.

Answer 2

Before the collision, one car had velocity v and the other zero, so the centre of mass of the system was also v/2 before the collision. The total momentum is the total mass times the velocity of the centre of mass, so the total momentum, before and after, is (2m)(v/2) = mv.

Step-by-step explanation: