A digital audio compact disc carries data along a continuous spiral track from the inner circumference of the disc to the outside edge. Each bit occupies 0.60 mm of the track. A CD player turns the disc to carry the track counter-clockwise above a lens at a constant speed of 1.16 m/s. Find the required angular speed (a) at the beginning of the recording, where the spiral has a radius of 2.40cm.

Answer 1

the inside track has a circumference of 2pi*2.4 = 4.8pi = 7.54cm

so, we have 116cm/s / 7.54cm/rev = 15.38 rev/s

angular speed a = 15.38*2pi = 96.6rad/s