Posted by Anab on .
A swimming pool filled with water to its edge, the depth of the water is 2m and an electric lamp is placed at a distance equals 8m from the edge of the pool over a column its height 6m. Calculate the length of nonapparent part from the pool bottom with the light does not reach to it, given the refractive index of water is 4?3.

Physics 
Elena,
I believe that the refractive index of water is n=1.3
Incidence angle α.
sin α =8/sqrt(8²+6)=0.8
sinα/sinβ=n =>
sinβ= sinα/n =0.8/1.3=0.61 =>β= 38°
x=h•tan β=2•tan38°=1.56 m