Question

The index of refraction of quartz is 1.46. What is the velocity of light in quartz?

Answer 1

Approximately
`2.05 * 10^(8)\; {\rm m\cdot s^(-1)}`.

Step-by-step explanation:

The refractive index
`n` of a material is the ratio between the speed of light in vacuum
`c` and the speed of light
`v` in that material. In other words:

`\begin{aligned}n &= (c)/(v)\end{aligned}`.

The speed of light in vacuum is
`c \approx 3.00 * 10^(8)\; {\rm m\cdot s^(-1)}`.

It is given that the refractive index is
`n = 1.46`. Rearrange this equation to find
`v`, the speed of light in this material:

`\begin{aligned}v &= (c)/(n) \\ &\approx \frac{3.00 * 10^(8)\; {\rm m\cdot s^(-1)}}{1.46} \approx 2.05 * 10^(8)\; {\rm m\cdot s^(-1)}\end{aligned}`.