*13-84. The 5-lb collar slides on the smooth rod, so that when it is at A it has a speed of 10 ft/s. If the spring to which it is attached has an unstretched length of 3 ft and a stiffness of k = 10 lb/ft, determine the normal force on the collar and the acceleration of the collar at this instant. 10 ft/s y=8-x² Ans: N=24.4 lb in +n and at,n = (180.2, 8.944) ft/s² 2 ft- x

Fig: 1