Question

The side of a fish tank is made up of a thick parallel sided piece of glass.The refractive index for glass is 1.52.A beam of light strikes the surface of the glass at an angle of 46 degrees with rspect to the normal.What direction will the beam move in the water.Show all CALCULATIONS

Answer 1

The light beam is refracted twice: first going from air to glass, and then from glass to water.
Nair = 1.00 angle A1 = 46
Nglass = 1.52 A2 = ?
Nwater = 1.33 A3 = ?

Snell's Law tells you that
1.00 sin A1 = 1.52 sin A2 = 1.33 sin A3
= sin 46 = 0.7193
Therefore
Sin A2 = 0.4732 A2 = 28.3 degrees
Sin A3 = 0.5408 A3 = 32.7 degrees

Since the glass wall is a parallel slab, the angle of the beam in the water, A3, does not depend upon the index of glass, but does depend upon the index of water.