You have been asked to design a "ballistic spring system" to measure the speed of bullets. A spring whose spring constant is k is suspended from the ceiling. A block of mass M hangs from the spring. A bullet of mass m is fired vertically upward into the bottom of the block. The spring's maximum compression d is measured.

A) Find an expression for the bullet's speed V. Express your answer in terms of the variables m, M, k, d, and constant g.
B) What was the speed of a 15g bullet if the block's mass is 2.2kg and if the spring, with k = 51 N/m , was compressed by 50cm.