Question

 A ray of light in corn oil is incident striking with an angle of incidence of 40 degrees on water. Calculate the angle of refraction to the nearest degree

Answer 1

The angle of refraction is given by the Snell's law:

$$\sin i\cdot n_1 = \sin r\cdot n_2$$

where $i = 40\degree$ is the angle of incidence, $r$ is the angle of refraction, and $n_1 = 1.47, n_2 = 1.33$ are the indices of refraction of the oil and water respectively.

Thus, obtain:

$$r = \arcsin\left( \sin i\cdot \dfrac{n_1}{n_2} \right) = \arcsin\left( \sin40\degree\cdot \dfrac{1.47}{1.33} \right) \approx 45\degree$$

Answer. $45\degree$.