A film of oil lies on wet pavement. The refractive index of theoil exceeds that of the water. The film has the minimum nonzerothickness such that it appears dark due to destructive interferencewhen viewed in red light (wavelength = 640.0 nm in vacuum).Assuming that the visible spectrum extends from 380 to 750 nm, forwhich visible wavelength(s) in vacuum will the film appear brightdue to constructive interference?
