RoseYoung

Question one

In the olden days we used to have milk in bottles delivered by the milkman. The cream would rise to the top of the bottle, and occasionally a bird would come along and peck at the top of the bottle to get at the cream! Compare the milk bottle where the cream is still uniformly mixed with the milk, to the same milk bottle later on when the cream has separated and risen to the top. Does the hydrostatic pressure at the bottom of the milk bottle remain the same during the phase separation of the cream? Assume the volume of the cream is 4.6 x 10-6 m3, the volume of milk (minus the cream) is 4.554 x 10-4 m3, density of cream is 994 kg/m3 and the density of the milk is 1033 kg/m3. The diameter of the bottle at the top is 26 mm (where the cream separates) and the average diameter for the rest of the bottle is 75 mm. Find the difference in hydrostatic pressure at the bottom of the bottle after the phase separation of the cream.