PURPOSE: To illustrate the Coriolis effect for a fluid source and sink.

DESCRIPTION: As the water tank rotates water is pumped out the bottom of the tank at a "LOW" and back into the bottom of the tank at a "HIGH." If the tank is rotated counterclockwise click for mpeg video, the water circulation is counterclockwise around the LOW and clockwise around the HIGH, as indicated by the flags. This simulates the Coriolis effect in the northern hemisphere, which produces cyclones around low pressure areas and anticyclones around high pressure areas. Rotating the tank clockwise, click for mpeg video simulates the effect in the southern hemisphere.

SUGGESTIONS: Use 8.5 VDC for the drive motor and 85 VAC for the pump.

See Question of the Week #89 for information on using this demonstration to enhance class involvement.

REFERENCES: (PIRA 1E30.36) See Demonstration Reference File for information on construction of this device as well as papers on the bathtub vortex and other Coriolis phenomena.

EQUIPMENT: Rotating tank, variac for pump motor, DC power supply for tank rotation.

SETUP TIME: 10 min.

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