Prof. K tried to devise an easier way of throwing a ball for her dog. The ball B has a mass of 0.5 kg and is restricted to move inside a frictionless slot. The rotation of the arm OA causes the ball to move. The rod is rotating with a constant angular velocity of 2 rad/s. Assume the ball only touches the bottom of the slot at all times and doesn't spin. Determine the force the arm exerts on the ball when θ = 30°. Express your answer using the Cartesian Coordinates shown. [Answer to Check: 1.54 N]