Demos: 2B-03 Water Seeks Own Level
This demonstration is similar to the Pascals Vases (2B - 2). Four glass tubes of varying shapes, all having the same height, are connected at the base. Water is poured into the vessel and regardless of the shape or volume, the water level is the same in each container, illustrating that liquid pressure is dependent upon vertical height only.
Directions: Pour the water slowly into one of the tubes and allow it to reach an intermediate level.
Suggestions for Presentation: Remind the students that liquid pressure depends on the height of the liquid column. But how is this height measured? In particular, the tube on the end is slanted so that it is considerably longer than the two vertical cylinders. To further complicate matters, one of the tubes is spiral shaped, so what is its vertical height?
Applications: Liquid storage devices may have differing shapes but the pressure at the bottom, say, is the same if the height of the liquid is the same.