A 3.0-kg sphere is suspended by a cord that passes over a 1.5-kg pulley of radius 3.5 cm. The cord is attached to a spring whose force constant is k = 86 N/m as in the figure below. Assume the pulley is a solid disk.

(a) If the sphere is released from rest with the spring unstretched, what distance does the sphere fall through before stopping?


(b) Find the speed of the sphere after it has fallen 25 cm.