Moving Source, Observer at Rest, derivation for Doppler effect

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SUMMARY

The discussion focuses on the conditions for the Doppler effect equation, specifically addressing the relationship between wave speed (v), frequency (f), and source speed (v_S). It is established that for the equation to hold true, the condition ##\frac{v}{f} ≥ \frac{v_S}{f}## must be satisfied to avoid negative wavelengths, which are physically impossible. The conversation also highlights the implications of supersonic speeds, indicating that objects moving faster than sound enter a different physical regime.

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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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