## June 2, 2011

### 3.18 Refractive Index

Recall and use the relationship between refractive index, angle of incidence and angle of refraction...

Refractive index is The ratio of the velocity of light in a vacuum to its velocity in a specified medium or simply put: how much the light is bent/refracted when it enters a specific medium.

to calculate the refractive index we use the formula:

$n = \frac{\textup{sin}\, i}{\textup{sin}\, r}$

n is the refractive index (this is purely a number and has no units)
i is the angle of incidence (in degrees °)
r is the angle of refraction (in degrees,
°)