Chapter 18.1, Problem 1PP

To determine

The angle of refraction.

Answer to Problem 1PP

  $26.23°$

Explanation of Solution

Given:

The angle of incidence of the laser beam, ${\theta }_1=37.0°$

Formula used:

Snell’s law of refraction,

  $n_1\sin {\theta }_1=n_2\sin {\theta }_2$

Where,

  $\begin{array}{l}{n}_1=\text{ index of refraction of first medium}\\ n_2=\text{ index of refraction of second medium}\\ {\theta }_1=\text{ angle of incidence}\\ {\theta }_2=\text{ angle of refraction}\end{array}$

Calculation:

It is known that,

Index of refraction of air, $n{1}_{}=1$

Index of refraction of ethanol, $n{2}_{}=1.361$

Then, using Snell’s law of refraction, angle of refraction will be,

  $\begin{array}{c}{n}_1\sin {\theta }_1=n_2\sin {\theta }_2\\ \left(1\right)\sin 37°=\left(1.361\right)\sin {\theta }_2\\ {\theta }_2={\sin }^{-1}\left(0.442\right)\\ =26.23°\end{array}$

Conclusion:

Hence, the angle of refraction is $26.23°$ .