The mechanism shown moves in the vertical plane. The vertical bar AB weighs 10 lb, and each

Question:

The mechanism shown moves in the vertical plane. The vertical bar AB weighs 10 lb, and each of the two links weighs 6 lb with mass center at G and with a radius of gyration of 10 in. about its bearing (O or C). The spring has a stiffness of 15 lb/ft and an unstretched length of 18 in. If the support at D is suddenly withdrawn, determine the initial angular acceleration ω of the links.