In an elastic collision, a 300 kg bumper car collides directly from behind with a second, identical bumper car that is traveling in the same direction. The initial speed of the leading bumper car is 4.90 m/s and that of the trailing car is 6.20 m/s. Assuming that the mass of the drivers is much, much less than that of the bumper cars, what are their final speeds (in m/s)?

Answer 1

If the speeds change by v, then they must balance out.

4.90+v = 6.20-v
2v = 1.30
v = 0.65

So, the leading car ends up at 5.55 m/s
the trailing car ends up at 5.55 m/s