A railroad freight car weighing 290 kN and traveling at 1.52 m/s overtakes one weighing 206 kN and traveling at 0.920 m/s in the same direction. The…

A railroad freight car weighing 290 kN and traveling at 1.52 m/s overtakes one weighing 206 kN and traveling at 0.920 m/s in the same direction. The cars couple together. What is the speed of the cars after the collision.