2. A ball B has a mass of m=0.5 kg and is at- tached to a cord which passes through a hole 4 in a smooth table. When the ball is r= 400 mm from the hole, it is rotating around the hole in a circle such that its speed is (g) 1.5 m/s. If, by applying the force F, the cord is then pulled downward through the hole, with a constant speed of u 2 m/s, determine the speed of the ball at the instant it is r = 200 mm from the hole. How much work is done by the force F in shortening the cord? 27 (Vg)2