Two bumper cars moving on a frictionless surface collide elastically. The first bumper car is moving to the right with a speed of 20.4 m/s and rear-ends the second bumper car, which is also moving to the right but with a speed of 9.16 m/s. What is the speed of the first bumper car after the collision? The mass of the first bumper car is 193 kg, and the mass of the second bumper car is 143 kg. Assume that the collision takes place in one dimension.