# Refractive index and speed of light

3instein

## Homework Statement

A slab of glass has a refractive index of 1.3. What will be the speed of light in this glass?

## The Attempt at a Solution

$$\frac{sin i}{sin r}=1.3$$

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## Answers and Replies

Homework Helper
Wrong equation. If you knew what this equation was, youwould know that you can't use it. The "i" and "r" are referring to angles, and are any angles given?

Try the equation that defines the index of refraction, n .

scivet
light speed in the media = c/n

Staff Emeritus