College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 39

A thin film of oil ( n = 1.25) is located on smooth, wet pavement. When viewed from a direction perpendicular to the pavement, the film reflects most strongly red light at 640 nm and reflects no green light at 512 nm. (a) What is the minimum thickness of the oil film (b) Let m 1 correspond to the order of the constructive interference and m 2 to the order of the destructive interference. Obtain a relationship between m 1 and m 2 that is consistent with the given data.