Rod OA rotates counterclockwise with a constant angular velocity of u . = 5 rad> s. The double collar B is pin-connected together such that one collar slides over the rotating rod and the other slides over the horizontal curved rod, of which the shape is described by the equation r = 1.5( 2 - cos u) ft. If both collars weigh 0.75 lb, determine the normal force which the curved rod exerts on one collar at the instant u = 120 . Neglect friction. N=2.77 lbs. Show steps.