A 1.81 kg block and a 3.62 kg block are initially at rest on a frictionless, horizontal surface, with a compressed spring of negligible mass between them. When the blocks are released, they move off in opposite directions. If the final velocity of the 1.81 kg block is 2.35 m/s to the left, what is the final velocity of the 3.62 kg block?
What is the magnitude?
and How much does the kinetic energy of the system increase?