An underwater diver sees the sun 50 degrees above the
horizontal.How high is the sun above

the horizon to a fisherman in a boat above the diver?

the horizon to a fisherman in a boat above the diver?

## Answer

Diagram:

fisherman 50% A 40° 50° diver

Apply the Snell’s at the point A. n sin40 n sin 6, Solve the equation fore (1.33)sin 40°= (1)sing sin , (1.33)in 40 0, = sin-11 (1.33)sin 400 = 58.70 From the diagram, the height of the sun above the horizon to the fisherman is, 9-90°-θ 900-58.70 31.3

Solution: The angle of incidence is given by, i = 90°-50° = 40° Let the angle as seen by the fisherman with horizon is r. Using Snell’s law, n, sin i=n, sin (90-r) n, sin i=n, cosr cosran, sini r=cosef 7, sini) r = cos-(1.33) (sin 409) = 31.250