Molecular-vibration waves {sound, physics} can move through materials.
process
Molecules from outside material can collide with material, causing material molecules to move. Molecular movement causes collision with adjacent molecules. First molecules bounce backward, and second molecules move, causing collision with adjacent molecules, and so on. Collisions send longitudinal wave down motion line.
Sound compresses {compression, sound} material in front of it, leaving slight vacuum {rarefaction} behind compression. Compression pushes next material bit forward. Original bit bounces back to original position, so material does not move. Compression wave travels through material. Only wave and energy move.
speed
Medium determines sound-wave speed. Sound-wave speed increases with stronger interactions between molecules. Wave frequency and amplitude do not affect speed.
amplitude
Sound has kinetic energy {loudness, sound}. Kinetic-energy increase increases sound-wave amplitude, by moving molecules farther. Frequency, wavelength, and speed do not affect wave amplitude.
pitch
Sound has number {frequency, sound} of vibrations per second. People can hear sounds of 20 to 20,000 Hz.
Sound has frequencies at two, three, four, and so on, times fundamental frequency {harmonics, physics}. Higher harmonics have lower amplitude.
Outside-material vibration frequency determines sound-wave frequency. Materials can have resonance frequencies.
Physical Sciences>Physics>Wave>Sound
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Date Modified: 2022.0224