When put in the tray, a compact disk is accelerated from rest to its initial playing speed.  The small and lightweight motors in disk drives are only capable of producing the angular acceleration shown.  If the disk  starts from rest, a) what is the velocity of point A after 1 second b)  If the initial play speed is 500 RPM, how long does it take to reach that play speed?  c) how many rotations has the disk made by the time it reaches intial play speed?  (Fun Fact: Note the use of "initial" because the play speed of a CD is not constant.  Rather,  speed is controlled relative to the location of the track being played)