Question

If a fish $40cm$ below the surface of a pond, how deep does it appear to an observer directly above? The refractive index of water is $1.33$.

Answer 1

Step-1: Given data

Distance of fish below the surface of a pond, $d=40cm$

Refractive index of water, $n=1.33$

Apparent depth, $h=?$

Step-2: Calculating the apparent depth of the fish

As we know,

$Refractiveindex\left(n\right)=\frac{Realdepth\left(d\right)}{Apparentdepth\left(h\right)}$

$$\begin{gathered} \Rightarrow 1.33=\frac{40cm}{h} \\ \Rightarrow h=\frac{40}{1.33} \\ \Rightarrow h=30.1cm \end{gathered}$$

Hence, the fish will appear at a distance of $30.1cm$ in the pool to the observer.