File talk:Pound-coin-floating-in-mercury.jpg
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Two effects let the coin float
[edit]
The copper alloy coin (density probably 8–10 g/ml) floats on mercury (d = 13,6 g/ml) because of 2 effects:
- surface tension AND
- floating force (Archimedes, density difference)
A clean coin would probably get "wetted" by mercury, but the pictured coin is NOT WETTED, possibly because a layer of fat and dirt.
This limits the the worthiness of the pictures.
The facts (two different upward orientated forces) should be mentioned in the description of the picture.
