Work, Energy & Momentum problems

A rifle bullet of mass 0.01 kg strikes and embeds itself in a block of mass 0.99 kg, which rests on a horizontal friction less surface. The block is attached to a coil spring as shown in the figure. The impact compresses the spring by 0.10 m. 

(a) Calculate the Velocity of the block immediately after the impact

(b) Calculate the velocity of the bullet just prior to hitting the block. 

(c) At the instant that the block momentarily comes to rest, what has happened to the momentum?

            (A) It is now Stored in the spring

            (B) It has been transferred to the earth

            (C) It has been dissipated as sound and heat

            (D) It has been lost because the collision was not perfectly elastic