Question

A layer of olive oil is poured on top of a layer of water in a container. A light ray passing from the oil to the water has an angle of incidence 70◦. Does this ray experience the total internal reflection?

Answer 1

yes if critical angle of oil is less than 70

Answer 2

Use Snell's Law to determine the incident ray's critical angle. A picture of the critical angle circumstance will help you realize how to do this. Then compare this number with your given number, (again, a picture will help) in order to arrive at a "yes" or "no."