Question

A ball is shot out of a spring and into a hollow ballast which then swings upwards 2.5 cm. The ball has a mass of 0.10 kg, the ballast has a mass of 0.50 kg and the spring constant is 500 N/m.

How fast was the ballast-ball system moving immediately after impact?
How fast was the ball moving immediately before impact?
How far was the spring compressed in order to release the ball with this speed?