# Dual sound source

In the above diagram, a sound source producing a sound of frequency $$f$$ is moving at a constant speed of $$v_s$$ to the right (in the direction of the red arrow). Let $$f_A$$ and $$f_B$$ be the frequencies detected by the sound detectors $$A$$ and $$B,$$ respectively. What is the ratio $$f_A:f_B$$?

The speed of sound ($$v$$) in the air is $$340 \text{ m/s}$$ and $$v > v_s$$.

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