A 2 kg mass moving to the right makes an elastic head-on

Last updated: 7/6/2022

A 2 kg mass moving to the right makes an elastic head-on collision with a 4 kg mass moving to the left at 4 m/s. The 2 kg mass reverses direction after the collision and moves at 3 m/s. The 4 kg mass moves to the left at 1 m/s. What was the initial velocity of the 2 kg mass? A. 1 m/s to the left B. 3 m/s to the right C. 4 m/s to the right D. 4 m/s to the left