A smooth 2-kg collar, shown in Fig. 13-9a, is attached to a spring having a stiffness k = 3 N/m and an unstretched length of 0.75 m. If the collar is released from rest at A, determine its acceleration and the normal force of the rod on the collar at the instant y = 1 m. C 0.75 m B 13 (a) k=3N/m (b) 19.62 N Fig. 13-9 0 Nc F