1. The problem statement, all variables and given/known data An old fashioned non-homogenized milk bottle is shaken up so the cream and milk are uniformly mixed. The bottle is then placed down, and the cream and milk begin to separate. Does the bottle weigh more or less when it is being carried or just after it is put down? Estimate the difference if any. 2. Relevant equations As far as I can see it's a purely qualitative problem. 3. The attempt at a solution I think the answer may be that it weighs more when it is put down, as the milk has momentum as it separates downwards which is greater than the momentum of the cream upwards as the milk has greater mass and they are both separating at the same speed. No idea how to estimate the difference in weight though... Anyone have any ideas about this problem?