Chladni Plate

For my wave apparatus, I designed an alternative version of a Chladni plate. Traditionally, a Chladni plate consists of a metal surface sprinkled with sand or salt, which reveals standing wave patterns when vibrated. However, instead of using a plate with dry particles, I modified the demonstration by using a shallow dish filled with water placed on top of a speaker. This setup allowed me to visualize wave patterns in the water using vibrations from the speaker at various frequencies, with an added visual effect of dye in the water to make the motion more distinct.

Wave pattern produced at 56 Hz

This apparatus demonstrates several key wave principles, including constructive interference, standing waves, and resonance.

  • Constructive Interference occurs when two waves combine to form a wave of greater amplitude. In this setup, the vibrations from the speaker continuously interact with the water, and at certain points, the crests of the waves reinforce each other, producing visible high points in the liquid.

  • Standing Waves form when incoming and reflected waves interfere in such a way that some points in the water (nodes) remain stationary while others (antinodes) vibrate with maximum amplitude. In the water dish, these standing waves create intricate patterns that shift with changes in frequency.

  • Resonance plays a crucial role in determining the patterns that appear. When the speaker vibrates at certain resonant frequencies, the water responds by forming stable wave structures that correspond to natural frequencies of the plate and water. At these frequencies the wave patterns in the water should hold still.




Through this experiment, I was able to explore the relationship between frequency and wavelength as well as frequency and wave speed. By adjusting the frequency of the speaker, I observed how different vibrational modes influenced the water’s motion. Lower frequencies resulted in larger, slower-moving waves, while higher frequencies produced finer, more intricate wave patterns. This aligns with the fundamental wave equation we learned the first week:
v=fλv = f\lambda

where vv is the wave speed, ff is the frequency, and λ\lambda is the wavelength. By observing the patterns, I could determine how frequency affects wavelength and overall wave behavior.


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