A rectangular block of glass is totally immersed in water (n = 1.33). If a ray of light traveling in the glass is incident on the interface with the water at an angle with respect to the normal that is greater than 53.1 degrees, it is found that no light is refracted into the water. For angles with respect to the normal less than 53.1 degrees, some of the light is refracted into the water.
What is the refractive index of the glass?