Solve the following problem given below:
Problem: An interference filter is constructed from two semireflecting mirrors (r2 = 0.5) separated by a film of plastic which has an index of refraction of 1.35. The pass band of the filter is to be centered at 550 nm for normal incidence.
Part I: Determine the thickness of the plastic film for the first two orders of interference.
Part II: Determine the Chromatic resolving power for these first two orders (normal incidence).
I don't just need an answer, work and explanations/walkthrough would be much appreciated! Thanks.