Determine:

a). The thinnest soap film (n = 1.33) in air that will result in constructive interference for reflected light of wavelength 656 nm.

b). What is the next thinnest soap film?

c). Your answers to a) and b) assumed that the rays were normal to the interface. Given the same film thickness: If you looked at the film from increasing angles of incidence, would the maximally enhanced wavelength be longer, shorter, or does it stay the same? Explain very briefly, using a diagram.