Calculate the water pressure in the pipes at the bottom of a high-rise building that is fed by reservoir 60 m above the roof top. and explain

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th