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 12.70 cm and a mass of 16.30 g. the laser scans at a constant tangential velocity of 1.150 m/s. assume that the music is first detected at a radius of 20.90 mm from the center of the disk. ignore the small circular hole at the cd's center.

Explanation:

Given

Diameter of CD

radius

mass of CD

Tangential velocity

music detected at

Moment of Inertia of disc

Work done is equal to change in kinetic Energy of CD

where angular velocity

colorectal cancer may also develop from areas of abnormal cells in the lining of the colon or rectum. this area of abnormal cells is called dysplasia and is more commonly seen in people with certain inflammatory diseases of the bowel such as crohn's disease or ulcerative colitis.