Doppler Effect

Front

Doppler Effect Noun

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[dop-ler uh-fekt]

Back

Doppler Effect

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A change in wave frequency due to relative motion between a wave source and an observer.

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Example: As the moving fire truck emits sound, the waves in front of it are compressed (higher pitch), while the waves behind it are spread out (lower pitch).

Front

Frequency Noun

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[free-kwen-see]

Back

Frequency

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The number of waves that pass a fixed point in a given amount of time, determining a sound's pitch.

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Example: This graph shows a wave with few cycles over time, representing a low frequency, like the low-pitched sound from a receding ambulance.

Front

Pitch Noun

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[pich]

Back

Pitch

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The perceived highness or lowness of a sound, which is determined by the sound wave's frequency.

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Example: This image shows that sound waves with a long wavelength have a low pitch, while sound waves with a short wavelength have a high pitch.

Front

Sound Waves Noun

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[sound wayvs]

Back

Sound Waves

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Vibrations that travel through a medium and are heard when they reach a person's or animal's ear.

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Example: A vibrating tuning fork creates compressions and rarefactions in the air, forming a longitudinal sound wave that travels to the ear.

Front

Wavelength Noun

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[wayv-length]

Back

Wavelength

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The distance between two consecutive corresponding points of a wave, such as two crests or two troughs.

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Example: This diagram shows that wavelength is the distance from one point on a wave, like a peak (compression), to the same point on the next wave.

Front

Amplitude Noun

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[am-pli-tood]

Back

Amplitude

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The maximum displacement of a wave from its equilibrium position, which relates to the loudness of a sound.

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Example: This diagram shows a wave and uses arrows to label the amplitude, which is the maximum distance the wave moves from its resting position.

Front

Crest Noun

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[krest]

Back

Crest

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The point on a wave with the maximum value of upward displacement within a single cycle.

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Example: This diagram shows a wave and uses an arrow to point to the 'Crest,' which is the highest point the wave reaches from its equilibrium position.

Front

Trough Noun

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[trof]

Back

Trough

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The point on a wave with the minimum value or lowest point of downward displacement in a cycle.

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Example: This diagram shows a wave, and the 'trough' is labeled as the lowest point of the wave's cycle, opposite the 'peak'.

Front

Redshift Noun

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[red-shift]

Back

Redshift

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The increase in the wavelength of light from a source moving away from an observer, shifting its spectrum redward.

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Example: This diagram shows that light from distant galaxies is stretched, causing its dark spectral lines to shift towards the red end of the spectrum (redshift).

Front

Spectrum Noun

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[spek-trum]

Back

Spectrum

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The range of frequencies or wavelengths of electromagnetic radiation, such as visible light, produced by a source.

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Example: This diagram shows the electromagnetic spectrum, the full range of light waves. It highlights visible light, the part we see as a rainbow.