At the instant shown, the 50-lb bar rotates clockwise at 2 rad/s. The spring attached to i...

At the instant shown, the 50-lb bar rotates clockwise at 2 rad/s. The spring attached to its end always remains vertical due to the roller guide at C. If the spring has an unstretched length of 2 ft and a stiffness of k = 12 lb/ft, determine the angle θ, measured from the horizontal, to which the bar rotates before it momentarily stops.