The speed of light in a material is $0.41 \mathrm { c }$ What is the critical angle of a light ray at the interface between the material and a vacuum?

Question

Quizplus · Accepted Answer

The critical angle can be calculated using the formula $\theta_c = \sin^{-1}(\frac{n_2}{n_1})$, where $n_1$ is the refractive index of the material and $n_2$ is the refractive index of the vacuum (1). The refractive index $n_1$ is the ratio of the speed of light in vacuum to the speed of light in the material, which is $\frac{1}{0.41}$. Calculating $\theta_c$ gives approximately 24°.

The Speed of Light in a Material Is 0.41c0.41 \mathrm { c }0.41c

The Speed of Light in a Material Is $0.41 \mathrm { c }$