SOUND WAVES
Sound Waves = Longitudinal Waves
Look for compressions and rarefactions... ...they go in all directions! |
Sound is LONGITUDINAL.
(But we imagine them as transverse waves, because those are easier to measure!) |
Here are two different ways to look at sound waves
and how they can change.
and how they can change.
Science vs. Music: Looking at Sound Waves
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As you watch this, look at the different ways they show sound waves.
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By controlling how fast the lightning flashes,
they are actually creating a sound wave! "440 Hz" means that the sound wave has 440 compressions per second. MORE ZAPS PER SECOND = MORE COMPRESSIONS PER SECOND MORE COMPRESSIONS PER SECOND = HIGHER FREQUENCY HIGHER FREQUENCY = HIGHER PITCH |
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Rubens' Tube: Measuring Sound Waves with Fire
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Chladni Plate: Seeing a sound wave spread
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What happens to the sound as the frequency goes up?
What happens to the wavelength when the frequency goes up? What is the relationship between frequency and wavelength? What is the relationship between frequency and pitch? What is the relationship between wavelength and pitch? |
An "oscilloscope" is a machine that transforms
LONGITUDINAL SOUND WAVES into transverse waves. In this demonstration, set both the V/div and ms/div dials to 1. Then generate different tones! Check their wavelength and frequency! |
This is the tone generator we use in class.
What happens to the pitch as you raise the frequency? |
The Medium
MEDIUM = The material a sound wave travels through
---Does the MEDIUM affect the sound? ---What happens if there is no MEDIUM for the sound to travel through? ---Do sound waves travel instantly or can their speed be measured? ---What different MEDIA (plural of MEDIUM) can sound pass through? |
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Can you hear sounds in space?
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Spoiler alert: You CAN'T hear sound in space. Why not?
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Steve Spangler does a lot with sound.
How are these experiments like the stuff we did in class?
What is he showing by making these sound waves?
How are these experiments like the stuff we did in class?
What is he showing by making these sound waves?
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The Human Ear
You need to know...
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How the Ear Works |
Vi Hart explains Sound Waves and the Human Ear
(Warning: some advanced stuff!) |
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