Chapter 18.1, Problem 5PP

To determine

The other medium if the light travels from air into another medium.

Answer to Problem 5PP

Crown glass

Explanation of Solution

Given:

The angle of incidence, ${\theta }_1=45.0°$

The angle of refraction, ${\theta }_2=27.7°$

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, $n{1}_{}=1$

Then, using Snell’s law of refraction, index of refraction of the other medium will be,

  $\begin{array}{c}{n}_1\sin {\theta }_1=n_2\sin {\theta }_2\\ \left(1\right)\sin 45°=n_2\sin 27.7°\\ n_2=1.52\end{array}$

And, it is known that the Crown glass has an index of refraction as $1.52$ .

Conclusion:

Hence the other medium is a Crown glass.