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**1. The problem statement, all variables and given/known data**

A dynamics cart with a mass of 2.2kg is moving at 33 cm/s to the right when it has a head-on collision with a second cart with a mass of 1.2kg moving in the opposite direction also at 33 cm/s. After the nearly elastic collision the first cart continues forward at 13 cm/s. What is the new velocity of the second cart?

**2. Relevant equations**

conservation of momentum mv initial=mv final

**3. The attempt at a solution**

(mv of cart 1- mv of cart 2- mv final of cart 1)/(m of cart 2)= 3.6 cm/s to the right

However that's not right, the answer should be 5.3 cm/s to the left, which honestly makes no sense. The teacher hinted that the solution would be counter-intuitive. However, when using the correct values I do not get the desired answer.

It would really help if someone could either confirm my findings or prove me wrong. Also, I know that in elastic collisions kinetic energy is conserved, and the in inelastic collisions, KE is not conserved. I wanted to confirm that in elastic collisions the two masses do not become one, as opposed to inelastic collisions in which they do become one single mass.