A puck attached to a string moves in a circular path on a frictionless surface, as shown in Figure 11-52. Initially, the speed of the puck is v and the radius of the circle is r. If the string passes through a hole in the surface, and is pulled downward until the radius of the circular path is r/2,

(a) Does the speed of the puck increase, decrease, or stay the same?

(b) Calculate the final speed of the puck.