Assume cart 1 has mass 387 gram and initial velocity +v10 = 8.21 meter per second, and cart 2 has mass 980 gram. Suppose the track is frictionless, and after the "elastic" collision cart 1 is moving at v1 = -3.440 meter per second and cart 2 is moving at v2 = 4.514 meter per second.
a) Find what percentage of the original energy was lost in this collision?
b) Find what percentage of the original linear momentum was "lost" due to external forces? (Memorize: linear momentum is a vector!)