Suppose you have a glass of water at room temperature. Now suppose you put the glass of water on a weighting scale. What the quantity actually measures ?
I have read that in fluids are basically lots of molecules in random motion and the intermolecular forces is really weak (I don't know if this is accurate or not). So when you put the glass of water on the scale, water particles are going in random motion.
So is the weight of the particles which are not touching the surface of the water glass (but are rather freely floating at the time of weighting and at random motion inside the glass) at the time of weighting contributing to the weight of the water glass as measured by the scale? Or is the weight of the glass same as the only the weight of the particles touching the surface of the glass at the time of measuring the weight (I don't think this is true since if you cool down it will become a solid so the weight will be same)?
Or is the weight which is measured is same as the water pressure at the bottom of the glass (I think this option is false too since you can create very high pressures at the bottom of the glass with some springs and pascal's theorem but that's not adding much weight )