64. A group of students examines the diffraction pattern created when red laser light with a wavelength of 650 nm is normal upon the surface of a CD. The students observe a first-order maximum 34" from the centre line on one side, and the other first-order maximum is 310 from the centre on the other side. (10.3) TM A (a) Use both measurements to determine the average slit spacing on the CD in metres. (b) Calculate the number of lines per centimetre that are etched onto the CD. (c) The CD has an etched radius of 4.0 cm, and it plays for 50 min. Determine how many rotations the CD will make if one line is read each rotation. (d) Determine the average rotational speed of the CD in revolutions per minute