A train blowing a whistle of frequency 320 Hz approaches an observer standing on the platform at a speed of 66 m/s. The frequency observed by the observer will be (given speed of sound = 330 ms$^{-1}$) __________ Hz.
Answer (integer)
400
Solution
$f=f_{0}\left(\frac{v}{v-v_{s}}\right)$
<br/><br/>
$$
\begin{aligned}
& f=320\left(\frac{330}{330-66}\right) \\\\
& =320 \times \frac{330}{264} \\\\
& =400 \mathrm{~Hz} .
\end{aligned}
$$
About this question
Subject: Physics · Chapter: Waves · Topic: Wave Motion and Types
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