# Height Ratio of A Coin below the Water

1. Apr 29, 2006

### 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 ....

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Last edited: Apr 30, 2006
2. Apr 29, 2006

### Staff: Mentor

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).