Height Ratio of A Coin below the Water

[willydavidjr]

A coin is at the bottom of a pool with a depth of $$h^l$$[m]. The diagram I provided below shows the coin can appear to be in a place shallower than its actual depth.

Looking perpendicularly onto the water surface ( $$i\cong 0, r\cong 0$$ ), the coin looked as if it were in a place with depth h[m]. FInd the ratio of $$h^l$$/h of the two heights.

This is the site of the diagram: www.geocities.com/willydavidjr/coin ...

 

[Doc Al]

Well, where's your solution? Apply Snell's law of refraction--and a bit of trig--and you can solve it. Hint: Consider small angles of incidence and refraction (close to the normal).