A 100 kg car moving rightward at 2 m/s collides elastically with a second car. Both cars end up bouncing off with the same speed (just in the opposite direction) than they had before they collided. What was the mass and speed of the second car? (​Adjust the Blue car mass to 100 kg and its velocity to +2 m/s. Set the bumper to Bouncy. For what value of Red car mass and velocity will the two bounce off without changing speed?)