3D40.30 - Chladni Plates
Video Credit: Jonathan M. Sullivan-Wood.
PRACTICE WILL BE REQUIRED FOR THIS DEMONSTRATION.
Clamp the plates to the table with the 'S' clamps. Sprinkle some of the fine sand or beads onto the plate. Bow the edge of the plate and watch the patterns that emerge.
Forced nodes can be produced by attaching a neodymium pair of magnets to the top and bottom of the plates.
With the mechanical oscillator this demo becomes very easy to do. The frequencies between 600 and 800 Hz. (700 Hz. is very good) will produce a number of patterns. Since the oscillator is nothing more than a very heavy duty speaker without a speaker cone it will produce a sizable amount of noise when the plates are resonating. The cover off the mousetrap demo will quiet this dramatically but will cut visibility. The oscillator will need to be run at 3/4 to 1 amp to make this work.
DO NOT RUN OVER 1 AMP - hence the amp meter. The oscillator has an upper limit amperage of l amp!!!
A variation is to use brightly colored sand. You could also use sand that has been mixed with some finely ground Tide or other "whitening" laundry powder. Mix some sand in a 5:1 ratio with the laundry powder and you will have sand that will fluoresce under a black light.
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