A constant horizontal force F = 300 N is applied to the linkage as shown. Assuming the 100 N ball to be originally at rest with the angle 0 =

60° as shown, calculate the velocity v of the ball(15 points) and the force exerted by the rod on the ball (5 points) as 0 approaches zero (where the ball reaches its highest position). The spring of stiffness k = 50 N/m has an un-stretched length of 1 m. Neglect the size of the ball and the thịckness of the linkage.