Wave Behavior and Energy

Front

Doppler Effect Noun

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[dop-ler uh-fekt]

Back

Doppler Effect

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The apparent change in the frequency of a wave caused by relative motion between the source of the wave and the observer.

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Example: As the ambulance moves, sound waves bunch up in front (high frequency/pitch) and spread out behind (low frequency/pitch) for stationary observers.

Front

Wave Interference Noun

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[weyv in-ter-feer-uhns]

Back

Wave Interference

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The phenomenon that occurs when two waves meet while traveling in the same medium, resulting in a new wave pattern.

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Example: This diagram shows how waves combine: constructive interference makes a bigger wave, destructive interference cancels waves out, and partially destructive interference makes a smaller wave.

Front

Superposition Noun

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[soo-per-puh-zish-uhn]

Back

Superposition

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The principle that when two or more waves overlap, the resulting displacement at any point is the vector sum of the individual waves.

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Example: When two waves overlap, their energies combine. The resulting wave's shape is the sum of the individual waves' heights at each point.

Front

Resultant Wave Noun

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[ri-zuhl-tnt weyv]

Back

Resultant Wave

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The wave that is formed by the superposition of two or more interfering waves, representing their combined effect.

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Example: This diagram shows two waves that are out of phase combining through destructive interference, which results in a new wave (the resultant wave) with a smaller amplitude.

Front

Constructive Interference Noun

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[kuhn-struhk-tiv in-ter-feer-uhns]

Back

Constructive Interference

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The superposition of in-phase waves that results in a new wave with a larger amplitude than the original waves.

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Example: When two wave crests meet, their amplitudes add together, creating a single, larger wave with a combined amplitude.

Front

Destructive Interference Noun

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[di-struhk-tiv in-ter-feer-uhns]

Back

Destructive Interference

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The superposition of out-of-phase waves that results in a new wave with a smaller amplitude or complete cancellation.

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Example: This diagram shows two waves (A and B) that are perfectly out of phase. When they combine, their peaks and troughs cancel each other out, resulting in a wave with zero amplitude (A+B).

Front

Phase Noun

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[feyz]

Back

Phase

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A description of a wave's position in its cycle at a specific point in time, often relative to another wave.

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Example: This diagram shows two waves that are 'in phase,' with their peaks and troughs aligned, and two waves that are 'out of phase,' with misaligned peaks and troughs.

Front

Phase Angle Noun

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[feyz ang-guhl]

Back

Phase Angle

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A measure of a waveform's shift in time relative to a reference, where a full period is represented by 2π.

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Example: This diagram shows how a phase angle measures a specific point along a wave's cycle, with a full cycle completing at 360 degrees.

Front

Beats Noun

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[beets]

Back

Beats

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The periodic variation in loudness of a sound that occurs when two sound waves of slightly different frequencies interfere.

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Example: This diagram shows how two waves with slightly different frequencies combine, causing alternating constructive (louder) and destructive (quieter) interference, creating the 'beat' effect.

Front

Beat Frequency Noun

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[beet free-kwuhn-see]

Back

Beat Frequency

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The rate at which the volume of an interfering sound pulsates, equal to the absolute difference between the two frequencies.

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Example: This diagram shows how two waves with slightly different frequencies combine. The resulting wave's amplitude gets bigger and smaller, creating the 'beat' effect.