Cart A has a mass of 3 kg and is moving to the right at 1 m/s. Cart B has a mass of 2 kg and is at rest. The carts have a perfectly elastic collision. Cart B starts moving to the right at 1.2 m/s. What is the final velocity of cart A? Be sure to include the speed and direction of cart A in your answer
momentum is conserved
3 kg * 1 m/s = (2 kg * 1.2 m/s) + (3 kg * v)