Question

(10. Explain why does a swimming pool appear
shallower than it actually is. Obtain an expression
for the normal displacement of an object immersed
in water.
​

Answer 1

it is due to refraction of light

expression ➡

shift(displacement) = real depth(1-1/ refractive index of water)

Answer 2

It's because of The refraction of light at the surface of water makes ponds and swimming pools appear shallower than they really are. If it meets the glass-air boundary at any angle other than 0o it will refract away from the normal. This is true for small angles – something else happens when the angles get larger.