The "grooves" on a compact disk "CD" can act light a diffraction grating when held up to the light.

. The "grooves" on a compact disk "CD" can act light a diffraction grating when held up to the light. Describe an experiment you could do to determine the number of grooves per mm on the CD. Show the equation(s) needed to calculate the number of lines per mm.

Please help, thnx in advance :)

use the famous Bragg's law of diffraction 2 d sin(theta) = n x (lambda), where 'n' is the number of lines