posted by opp on .
How much work is done by the motor in a CD player to make a CD spin, starting from rest? The CD has a diameter of 12.8 cm and a mass of 15.7 g. The laser scans at a constant tangential velocity of 1.23 m/s. Assume that the music is first detected at a radius of 19.1 mm from the center of the disk. Ignore the small circular hole at the CD's center.