A ray of light is travelling in a glass cube that is totally immersed in water. You find that if the ray is incident on the glass-water interface at an angle to the normal greater than 48.7°, no light is refracted into the water. Calculate the refractive index of the glass.
Refractive Index of Water: 1.33
The Attempt at a Solution
Na = Nb*Sin(Θb)/Sin(Θa)
Na = 1.33*Sin(90°)/Sin(48.7°)
Na = 1.77
Glass Cube Refractive Index = 1.77
I feel that I have made an error or that I'm not grasping the concept correctly. Any guidance or explanation would be highly appreciated.