Question

When reading data from a CD, the CD player must vary the discs rotational speed so that it reads data at a constant rate. The rate at which the the CD reads data is related to the linear velocity of a point on the disc. Assume the inner radius of the disc is 36.0 mm and the outer radius is 118 mm, and that the linear velocity required to read data a constant rate is 1.70 m/s.

1.What frequency of rotation is required when reading data at the inner edge? Enter your answer in rpm (revolutions per minute).

2.What frequency of rotation is required when reading data at the outer edge? Enter your answer in rpm (revolutions per minute).

3.To begin to read data on the outer edge of the disc, the CD (which is initially stationary) accelerates to the required angular speed in 0.15 s. What was the magnitude of the angular acceleration?

4.What was the magnitude of the angular displacement during that time? Your answer should be in radians.

Answer 1