Moving Source, Observer at Rest, derivation for Doppler effect

AI Thread Summary
The discussion centers on the conditions for the Doppler effect equation, specifically whether the assumption that v/f is greater than or equal to v_S/f is necessary to avoid negative wavelengths. It highlights that if the source moves faster than the speed of sound, it enters a supersonic regime, which alters the physical principles at play. Participants express gratitude for clarifications regarding these assumptions. The conversation emphasizes the importance of understanding the implications of speed in relation to wave behavior. Overall, the thread seeks to clarify foundational concepts in wave physics related to the Doppler effect.
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Homework Statement
Please see below
Relevant Equations
Please see below
For this,
1685661674611.png

Does someone please know whether they assume for the equation highlighted that ##\frac{v}{f} ≥ \frac{v_S}{f}## since otherwise the wavelength would be negative (which I assume is impossible)?

Many thanks!
 
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ChiralSuperfields said:
Homework Statement: Please see below
Relevant Equations: Please see below

For this,
View attachment 327342
Does someone please know whether they assume for the equation highlighted that ##\frac{v}{f} ≥ \frac{v_S}{f}## since otherwise the wavelength would be negative (which I assume is impossible)?

Many thanks!
The object would be moving faster than the sound speed; i.e., supersonic which is a different physical regime.
 
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Frabjous said:
The object would be moving faster than the sound speed; i.e., supersonic which is a different physical regime.
Thank you for your reply @Frabjous!
 
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