Solution: Light of wavelength 475nm in vacuum enters a plastic as shown in Fig. 1. Measurements of the light in the plastic indicate that its wavelength there is 394 nm. What is the frequency of the light in the plastic? 

Problem

Light of wavelength 475nm in vacuum enters a plastic as shown in Fig. 1. Measurements of the light in the plastic indicate that its wavelength there is 394 nm. What is the frequency of the light in the plastic?