A 5 gram bullet moving with an initial speed of 400m/s is firedinto and passes through a 1 Kg block. The block, initially atrest on a frictionless, horizontal surface, is connected to aspring with k = 900 N/m. If the block moves a distance of 5cm to the left after impact, find
(a) the speed at which the bullet emerges from the block
(b) the energy lost in the collision