A ball B has a mass of mB=0.5kg and is attached to a cord which passes through a hole A in a smooth table. When the ball is r1=400mm from the hole, it is rotating around the hole in a circle such that its speed is (vB)1=1.5m/s. If by applying the force F, the cord is then pulled downward through the hole, with a constant speed of uc=2m/s, determine the speed of the ball at the instant it is r2=200mm from the hole. How much work is done by the force F in shortening the cord