Question

A ray of light in air-incident at an angle of 45° on the boundary with water. Calculate the angle of refraction if the relative refractive index of air is 0.55?

Answer 1

Given:

$\theta_i=45^\circ$

$n=0.55$

The Snell-Decart law says

$$\frac{\sin\theta_i}{\sin\theta_r}=\frac{1}{n}$$

The angle of refraction

$$\theta_r=\sin^{-1}(n\sin\theta_i)$$

$$\theta_r=\sin^{-1}(0.55*\sqrt{2}/2)=23^\circ$$