Amy (60kg) initial velocity of 7.5 m/s is skating towards bob (90kg) and initial velocity of 4 m/s. Bob is skating away from amy but since she is moving faster they collide. Assumeing the collision is totally inelastic what is their final speed? Assuming their collision is perfectly elastic what are each of their final speeds? And if bobs final speed is 5 m/s determine amys final speed and percent of kinetic energy lost in the collision.