A railroad car with a mass of 1.81 104 kg moving at 3.04 m/s joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.32 m/s.

What is the decrease in kinetic energy during the collision?

1 answer

I was going to answer this one, but drwls answered it in the first post in related questions.