Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538
Demonstrations are cataloged according to PIRA Bibliography
PLEASE REQUEST DEMOS WELL IN ADVANCE
Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.
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You have selected the following Demos:
Purpose:To demonstrate different vibrational resonances of thin plates.
Procedure:Attach support rod to the plate and clamp to the edge of the table so that the plate is horizontal. Sprinkle sand over the surface and bow the edge of the plate with the bow in the vertical position. Many different modes can be obtained by bowing in different spots and by placing a finger along the edge of the plate. This does take considerable pratice to be effective.
Hints:Using a PASCO or other wide range generator is much easier. Most cool looking shapes are at the high(er) (around 1KHz) frequencies. Start with small amount of "sand", listen to the increased amplitude of the annoying high frequency sound and sprinkle more magic dust to get a good figure. Some additional patterns for square plate are provided in the picture gallery. They are 707, 776, 970, and 1658 Hz oscillator frequency correspondingly.