Problem: An underwater diver sees the sun 59 degrees above horizontal.How high is the sun above the horizon to a fisherman in a boat above the diver?Express your answer using two significant figures.φ= _____________degrees

The angle above horizontal = 59°

We'll define the angle of incidence as the angle at which the ray from the sun strikes the interface.

The boat is at the boundary. Therefore, the target is angle relating h₁.

The angle of refraction = 90 - 59 = 31°

Use Snell's Law to relate the Angle of Incidence with the Angle of Refraction:

$\boxed{\begin{array}{rcl}{\mathbf{n}}_{\mathbf{i}}\mathbf{ }\mathbf{sin}\mathbf{ }{\mathbf{\theta }}_{\mathbf{i}}& \mathbf{=}& {\mathbf{n}}_{\mathbf{r}}{\mathbf{sin\theta }}_{\mathbf{r}}\end{array}}$