Rod OA rotates counterclockwise with a constant angular velocity theta(prime)= 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 teh horizontal curved rod, of which the shape is described by the equation r=1.5(2-cos(theta)ft. If both collars weigh .75 lb, determine the normal force which the curved rod exerts on one collar at the instant theta=120 degrees. Neglect friction.