PURPOSE: To illustrate water wave solitons and some of their properties.

DESCRIPTION: A narrow rectangular trough contains about 1.5 cm of water. With the water trough vibrating vertically at about 10 Hz, a soliton can be created by moving a small paddle back and forth across the trough. The soliton can be pushed along by sticking the paddle into the trough and moving it slowly toward the soliton. Two solitons can be created at different positions in the tank. If one is pushed toward the other, they will attract each other if they are in phase, and repel each other if they are out of phase. One soliton can be pushed toward a second out-of-phase soliton, causing the second soliton to move down the tank.


REFERENCES: (PIRA 3B45.30) See Demonstration Reference File for construction and operation details of this soliton demonstration and for articles on solitons.

EQUIPMENT: Tank with paddle, water, and power supply, withdigital voltmeter for calibration.

SETUP TIME: 10 min.

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