A source of sound moves towards a stationary observer. The observer detects a frequency that is
Answer and explanation
Correct answer: D. higher than the frequency emitted by the source
- Step 1: Waves in front of a moving source are compressed, so the observer hears a higher frequency.
Answer
higher than the frequency emitted by the source.
Why not the others: lower than the frequency emitted by the source: this happens when the source moves away from the observer. equal to the frequency emitted by the source: relative motion changes the observed frequency (Doppler effect). higher, with a faster speed of sound: the speed of sound in air stays the same; the wavelength is compressed.
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