32. Increasing the amplitude of a sound wave produces a sound with
1. lower speed
2. higher pitch
3: shorter wavelength
4. greater loudness

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