5.1.4 Interference, Standing Waves, & Resonance

​•INTERFERENCE – the result of two waves meeting in a medium.

–CONSTRUCTIVE – results in greater amplitude.

–DESTRUCTIVE – results in lower amplitude.

–Superpositioning

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•“In phase” interferes CONSTRUCTIVELY

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•“180° out of phase” interferes DESTRUCTIVELY

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​All mediums have a NATURAL FREQUENCY that corresponds to their atomic structure.

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Exciting this frequency causes large AMPLITUDE vibrations in the medium

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If the frequency is excited with enough ENERGY the medium may become damaged or even shatter.

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If two materials have the same (or close) natural frequencies then vibrations may be passed from one material into the other.

EX. Blowing across an empty bottle

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