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9th Grade Science Fair ProjectsInformation for 9th grade science fair projects you can do on sound waves. What is sound? It is a waveform created by some type of vibration. These waves will travel through matter such as air, water, wood, steel, and many others. Your voice, music, thunder, etc., are all examples of sound waves that we can hear. Some materials do not carry sound waves well and are considered insulators. They will either dampen or prevent sound from tarveling through them. A vacuum(which is the absence of air or other gas) will prevent sound from moving through it. Nothing is present in a vacuum to carry the sound waves. So since space is a vacuum, you would not be able to hear sounds there.
Characteristics Of Sound Waves To Give You Ideas For Your 9th Grade Science Fair ProjectsAmplitude- This expresses how loud the sound is. A common unit of measuring sound is called the decibel or dB for short. This is a logarithmic scale so each decibel number higher a sound is means its 10 times greater than the number before it. Something with a noise level of 20 decibles is 10 times louder than a noise of 19 decibels for example.Speed- How fast sound travels depends on several factors in addition to the type material its passing through. The speed of sound through air depends on the air temperature and the altitude where the sound is. Air is more dense at sea level than at higher altudes so it moves faster there. The warmer the air, the faster sound travels through it and colder the air the slower it moves. Frequency- This is a measure of how many waves pass a point in a particular time. This is related how closely compacted the waves are together. That is determined by the material itself, how fast its vibrating, and its temperature. Wavelength- A measure of the distance between peak of one wave and the peak of the wave next to it.
The Decibel Range Of Some Common Sounds0-30 dB...Very quiet50-70 dB...This would be similar to people talking in a normal tone. 71-90 dB...Loud enough to be distracting such as traffic on a street. Over 90 dB...This level of sound can cause hering damage over a period of time. A concert might be an example of this sound level. 200 dB...A space shuttle launch.
You have probably noticed a lightning flash and then heard the thunder a few seconds later. This is because the lightning is some distance from you and light travels far faster than sound. So you have the delay between the flash and hearing the sound of the thunder. By thinking about these characteristics of sound waves I am sure you can think of some great ideas for your 9th grade science fair projects.
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