Answer to Question #284531 in Optics for luna

Question

The beam of parallel light rays falls onto the surface of water under the angle

60°

. The width of the beam in the air is 10 cm. Find the width of the beam in the water.

Answer 1

$n=\frac{\sin\alpha}{\sin\beta},\implies \beta=40.5°,$

$b=\frac{a\cos\beta}{\cos\alpha}=15.2~cm.$