Problem: A scuba driver in a lake aims her underwater spotlight at the lake surface. (a) If the beam makes a 75° angle of incidence with respect to a normal to the water surface. Is it reflected, transmitted, or both? Find the angles of the reflected and transmitted beams (if they exist).(b) Repeat for a 25° angle of incidence.

FREE Expert Solution

(a)

The critical angle for water-air surface:

$\overline{){{\mathbf{\theta }}}_{{\mathbf{C}}}{\mathbf{=}}{\mathbf{s}}{\mathbf{i}}{{\mathbf{n}}}^{\mathbf{-}\mathbf{1}}{\mathbf{\left(}}\frac{{\mathbf{\eta }}_{\mathbf{a}}}{{\mathbf{\eta }}_{\mathbf{w}}}{\mathbf{\right)}}}$

Problem Details

A scuba driver in a lake aims her underwater spotlight at the lake surface.

(a) If the beam makes a 75° angle of incidence with respect to a normal to the water surface. Is it reflected, transmitted, or both? Find the angles of the reflected and transmitted beams (if they exist).

(b) Repeat for a 25° angle of incidence.