A 4-lb ball B is traveling around in a circle of radius r1, = 3 ft with a speed (vB)2, = 6...

A 4-lb ball B is traveling around in a circle of radius r1, = 3 ft with a speed (vB)2, = 6 ft/s. If the attached cord is pulled down through the hole with a constant speed vr = 2 ft/s, determine how much time is required for the ball to reach a speed of 12 ft/s. How far r2 is the ball from the hole when this occurs? Neglect friction and the size of the ball.