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Mar28-12, 09:14 PM
P: 292
It's spring break right now, so I thought I'd take the time to brush up on stat mech and thermo before classes resume next week...

My question is this (Problem #1096 in "Problems and Solutions on Thermodynamics and Statistical Mechanics" Edited by Yung-Kuo Lim):

A flask of conical shape contains raw milk. The pressure is measured inside the flask at the bottom. After a sufficiently long time, the cream rises to the top and the milk settles to the bottom (the total volume of the liquid remains the same). Does the pressure increase, decrease, or remain the same? Explain.

Instinctively, I wanted to respond that the pressure remains the same, but the book says it doesn't. The final "solution," as presented in this book, is that the pressure decreases. Does that seem right to you?

Here's the link to the Google Book preview so that you can see the full solution yourself:
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