A stationary source emits a whistle at a frequency of $200 ext{ Hz}$. If the velocity of propagation of sound is $340 ext{ ms}^{-1}$, then the observed frequency, if the observer is moving away from the source at $25 ext{ ms}^{-1}$, will be [MP PMT 2013]

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A stationary source emits a whistle at a frequency of $200	ext{ Hz}$. If the velocity of propagation of sound is $340	ext{ ms}^{-1}$, then the observed frequency, if the observer is moving away from the source at $25	ext{ ms}^{-1}$, will be [MP PMT 2013]

Aicharya · Accepted Answer

As we know, $f' = f\left(\frac{v}{v - v_s}ight)$ Given, $f = 200	ext{ Hz}$, $v = 340	ext{ ms}^{-1}$, $v_s = 25	ext{ ms}^{-1}$ From Doppler's effect, $f' = 200\left(\frac{340}{340 - 25}ight) = \frac{200 	imes 340}{315} \Rightarrow f' = 215	ext{ Hz}$

A stationary source emits a whistle at a frequency of $200\text{ Hz}$. If the velocity of propagation of…

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