Question

Walt and Wolfie collide in bumper cars of mass 50 kg each. Walt has a mass of 60 kg, and Wolfie has a mass of 80 kg. Walt strikes Wolfie from the rear at V = 7.9 m/s. If the collision is elastic, and Wolfie is initially at rest, what is Wolfie's speed after the collision (in m/s)? Assume that the collision is "one-dimensional", i.e., all the motion is in the "x" direction.