Sound in air is a longitudinal pressure wave. Particle motion is mainly parallel to the direction the disturbance travels. Alternating compressions and rarefactions transfer energy while particles oscillate around their resting positions. This model isolates an orderly wave; it does not show the much faster random thermal motion of real air molecules.
Light, sound and electricity · Discover & try
How does a vibration travel as sound?
Reading level 3 of 5 · IndependentChange
Word help
vibration
Repeated movement around a resting position.
compression
A region where the model particles are closer together.
Watch · Try · Explain
See how it works
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Slowed, one-dimensional air-particle model; particle spacing and motion are exaggerated and no sound plays.
What to look for
- Crowded regions move along the row
- The marked particle stays local
- The source moves back and forth
Explain what you noticed
A doorbell is 10 metres from a listener. What does an air particle beside the bell do as its sound passes?
Keep this idea: A sound pattern travels while air particles oscillate locally.
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Source material checked 2026-10-28. Explanations and activities by Nepedia. Source links do not imply endorsement.
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