PURPOSE: A trick to challenge the students.

DESCRIPTION: The liquid level in the left side of the U-tube is higher than that in the right side of the U-tube. How does one explain this?

Two immiscible fluids of different density which are identical in physical appearance are in the two ends of the U-tube. The point where they meet (which could be easily seen) is covered by the clamp which holds the U-tube.

SUGGESTIONS:

See Question of the Week #167 for information on using this demonstration to enhance class involvement.

REFERENCES: (PIRA unknown.)

EQUIPMENT: U-tube on stand.

SETUP TIME: None.