Determine the direction in which a fish under water sees the setting sun. Given, for water `mu = 1.33`.

Explanation

In Fig., the setting sun is in the direction of water surface. A ray of light from setting sun enters the eye of the fish when apparent position of the makes critical angle `C` with the vertical.

`:. sin C = (1)/(mu) = (1)/(1.33) = 0.7518`
`C = sin^(-1) = (0.7518) = 48.7^(@)`
Hence angle between apparent position of the sun and horizontal is `theta = 90^(@) - 48.7^(@) = 41.3^(@)`