My PBL

Materials Pictures:

INTRODUCTION :

What are Chladni Plates?

Chladni Plates were invented by Ernst Chladni, a German physicist/musician who enjoyed conducting many researches. One of these was that of the Chladni Plates, which involves resonance and the traveling of sound waves through a stiff surface. Through this, he started to be called the "father of acoustics". These Chladni Plates not only help us have a deeper understanding about sound wave traveling and vibrating plates, but it also contributed to one of today's world major fields: music. With th einvention of the Chladni Plates, the visualization of the traveling of sound waves in a 2D object became possible.

MATERIALS:

1 square chladni plate

1 violin chladni plate

Silica sand

1 Mechanical vibrator

1 Sine wave generator

big clear box (so silica sand may fall in it and be recycled, while you can still se what is happening)

PROCEDURE:

1. Take out all materials and have them ready.

2. Set up mechanical vibrator and one chladni plate.

3. Connect sine wave generator to power source, and other end to mechanical vibrator.

4. Put mechanical vibrator on the box.

5. Spread some silica sand onto the plate.

6.Change the frequency on the sine wave generator. (if using square chladni plate start at 100, if using violin chladni plate start at 300)

7. Start increasing frequency by hundreds until you get to 800 to see the different changes in the shapes.

SCIENTIFIC PRINCIPLE:

What is involved in this project about physics, is the resonance, how sound waves travel, and the vibrating of an object. Yes! basically, physics is everywhere. Especially in this project.

This amazing thing is no magic. The thing that happened was that the sand was being accumulated in the nodes of the wave. also, by ajusting the frequency and amplitude better patterns will be developed.

Resonance: Causes the plate to vibrate in opposite directions causing the nodal lines.

Vibration: Technique show the different modes of vibration.

Chladni patterns can also be formed by using circular or rectangular metal plates on a mechanical driver controlled by a signal generator. This method avoids having to practice your bowing. The patterns are now different since they have antinodes at the center (which is being vibrated) rather than nodes with the center rigidly attached and the edge bowed.

Square chladni plate

Violin Chladni Plate

Silica Sand

Mechanical Vibrator

Sine Wave generator

All Put Together