C dt. When light enters a substance such as glass its speed is reduced based on how it hits the atoms in the material. The index of refraction of a material can be calculated by the following equation.
N c v where n refractive index.
The index of refraction n of the material. Similarly the speed of electromagnetic waves in wire cables is slower than c. The index of refraction values provide a measure of the relative speed of a light wave in a particular medium. The speed of light is maximum in.