A 64 g ball is shot into the barrel of a spring-gun with a speed of 24 m/s. The sprig-gun has a mass of 280 g and is initially at rest on a frictionless surface. The ball sticks in the barrel at the point of maximum compression of the spring. Assume that friction between the ball and the barrel is negligible. Note that momentum is conserved as the ball becomes stuck in the spring-gun because the net-force on the system containing both the ball and the spring-gun is zero. A ball is fired into the barrel of a spring-gun. What is the change in kinetic energy of the ball and spring-gun