Photo by V. Miller
April 27, 2005
Glass Sounds
How Low Can You Go?
David R. Sharples, 12, East Windsor, N.J.
Finalist, Discovery Channel Young Scientist Challenge, 2004
Project background: David became fascinated with resonant frequency after watching the famous 1940 video of the Takoma Narrows bridge twisting apart. He originally wanted to find the frequency and intensity of sound that was sufficient to break a wine glass. David began exploring the idea with an experiment in which he tested how the resonant frequency of the glass changed depending on the liquid inside.
Tactics and results: David generated tones of various frequencies with a laptop computer and a guitar amplifier. He placed a wine glass near a decibel meter hooked to an oscilloscope, which would measure the frequency generated. He placed a piece of paper on top of the glass and filled the glass with, in turn, alcohol, cooking oil, water, syrup, and molasses. He ran a series of trials with various frequencies and recorded the frequency at which the paper vibrated most vigorously—the glass's resonant frequency.
 |
| Photo by V. Miller |
David found that denser liquids lowered the resonant frequency.
Read the latest science fair news
Get a science fair tip
Browse a list of science fair topics
Talk Back:
Do you have any comments about this ScienceFairZone? Send them
to us using the form below.
|