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I came across this problem which had the given setup: A drop of water (mass = 70 mg) was introduced between two glass plates, assume wetting to be complete, find the attractive force between the plates.

So, this can be solved by getting the difference of pressure due to the atmosphere and the pressure due to water , using surface tension.

Now, let's assume that one of the plate is lying on a table, then there's water layer above it, and then there's another plate above the water.

My question is that, if we consider the plate lying on top of it, then there's a force which acts downwards due to pressure difference and then there's the weight of plate that acts downwards.

What's the force which is acting upwards and keeping the plate in equilibrium.

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Assuming that surface tension prevents a thin layer of water from flowing from between the plates, then the weight of the plate above generates pressure in the water and the water responds with a reaction force.

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I think it should be the normal reaction of the system below the plate. It is just like why a book kept on table does not fall through the table.

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