Refraction of light

Question

A stone placed at the bottom of a water tank appears to be raised by 80 cm.  If the refractive index of water is 1.33, find the actual depth of water in the tank.

Answer 1

Data Analysis

 Apparent depth= 80cm                       Refractive index of water= 1.33         Real/Actual depth = ?

Solution

Refractive index(n)= [Real depth(O) ÷ Apparent depth(I) ]                        Implies that, O= n × I=1.33×80cm= 106.4cm. And 106.4cm is equivalent to  1.064m

Answer 2

We know that:  Real Depth / Apparent Depth = Refractive Index

So for our question , the actual depth = 80 cm x 1.33 = 106.4 cm