Question

A fish is 1.2 m beneath the surface of a still pond of water. At what maximum angle can the fish look toward the surface (measured with respect to the normal to the surface) in order to see a fisherman sitting on a distant bank? (for water, n = 1.333)

Answer 1

Answer:

49°

Explanation:

Depth at which the fish is found= 1.2 m

refractive index for water, n= 1.333

Using snell's law we can write

$\frac{sin {i}}{sin {r}}=n$

i and r are angle of incidence and angle of refraction respectively

Here, r= 90°

put value of n and r to get i

$\frac{sin {i}}{sin {90}}=1.333$

sin 90= 1  and $sin^{-1}(1.333)= 49°$

implies that i= 49°

hence, the maximum angle of incidence i= 49°