cpxuvs said:
The supplement of my question:A piece of wood floats on the surface of the water.Similarly,what happen when an object floats on the stratified surface of two liquids?
here one also a an object floating at the interface between two fluids - air and water.
The wood motion can depend upon the motion of the interface - goes without saying.
The interface can be motionless and calm, in which case the wood would rest also calmly, and one could draw a horizontal line on the wood signifying the unchanging interface.
If the interface has movement, then the wood would be affected by that movement.
The interface can exhibit a sloshing effect as indicated in post #2
if the wood length is a fraction of the wavelength then the wood would follow the surface, with its ups and downs, and inclinations.
If the wood is a multiple of the wavelength, then a damping effect could be possible, so that the movement of the wood is not as drastic as noted above.
Since you are considering using this technique for leveling, or height purposes for the polishing machine - nonuniform polishing process was mentioned which I do not know exactly what that means - the machine will set up at the interface a higher frequency of vibrations, or multiples, upon which the wood will react to in a manner.
That also I would think has to be considered as well as the movement of the machine in its conceivable to and fro movement.
for air and water one can notice the wave action, sloshing, and endless ripples at the air-water interface.
A boat will not react very strongly to the ripples, somewhat to the wave action, and definitely to the sloshing.
A bug, or a short stick on the surface will react to all three movements of the interface.
By all means, I could be all quite incorrect on my interpretation.
But does that describe somewhat your question, and does it help.
