Radar consists of electromagnetic waves. a warplane is rendered invisible to enemy radar by applying an antireflective polymer coating. if radar waves have a frequency of 10 ghz (giga = 1e9), and the index of refraction of the polymer for these waves is 1.50, what is the minimum thickness of the antireflective coating? (c = 3e8 m/s. the index of refraction of air is ~1, and that of the fuselage is larger than for the polymer coating)