Question

A ray of light is incident on the surface of a crown glass plate at an angle of 30 with the normal. Determine the angle between the refracted ray and reflected ray.

Answer 1

The Snell's law says

$$n_i\sin\theta_i=n_t\sin\theta_t$$

$$\theta_t=\sin^{-1}\frac{n_i\sin\theta_i}{n_t}$$

$$\theta_t=\sin^{-1}\frac{1.0*\sin30^\circ}{1.52}=19^\circ$$

$$\theta_r=\theta_i=30^\circ$$

The angle between the refracted ray and reflected ray is given by

$$\theta=180^\circ-(\theta_r+\theta_t)\\ =180^\circ-(30^\circ+19^\circ)=131^\circ$$