Modes of a Drum
Safety Warnings
Warning: UV Light Exposure
Warning: Volume Levels
Purpose
Visualizes 2D standing wave modes on a circular membrane driven by a speaker. A fluorescent rubber sheet under UV light reveals nodal patterns as the driving frequency is swept, connecting to Bessel function solutions and quantum eigenstate analogies.
Figure 1:
Complete setup: fluorescent rubber membrane stretched over a drum shell, UV panel light on a stand, signal generator and amplifier. The speaker cone is mounted beneath the membrane.
Figure 2:
Standing wave mode visible as a pattern of bright and dark stripes across the fluorescent membrane. The nodal lines appear as dark regions where the membrane displacement is zero.
Figure 3:
Different vibrational mode at a different driving frequency. Each resonant frequency produces a unique nodal pattern.
Figure 4:
Another vibrational mode showing a different nodal pattern. Sweeping the frequency reveals the rich spectrum of modes on a circular membrane.
Equipment
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Demo Apparatus
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