A 323 gr bullet B (1 lb = 7000 gr) moving at v0 = 800 ft./s hits a 4 lb block A that is in...

A 323 gr bullet B (1 lb = 7000 gr) moving at v0 = 800 ft./s hits a 4 lb block A that is initially at rest. The block is attached to an uncompressed spring of stiffness k = 6000 lb/ft. After the collision, the bullet becomes embedded in the block. Neglecting friction between the block and the surface on which it slides, determine the compression of the spring required to bring the system to a stop.

Figure P5.68