A whistle emitting a loud sound of frequency | vedclass

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(C) The source of sound is moving in a circle,so its linear speed $v_s$ is given by $v_s = r\omega$.Given $r = 2 \,m$ and $\omega = 15 \,rad/s$,we hav

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$1.2$

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(C) The source of sound is moving in a circle,so its linear speed $v_s$ is given by $v_s = r\omega$.Given $r = 2 \,m$ and $\omega = 15 \,rad/s$,we have $v_s = 2 	imes 15 = 30 \,m/s$.The speed of sound is $v = 330 \,m/s$.According to the Doppler effect,when the source moves towards the stationary observer,the observed frequency is $f_{\max} = \left(\frac{v}{v - v_s}ight) f$.When the source moves away from the stationary observer,the observed frequency is $f_{\min} = \left(\frac{v}{v + v_s}ight) f$.The ratio of the highest to the lowest frequency is:$\frac{f_{\max}}{f_{\min}} = \frac{\left(\frac{v}{v - v_s}ight) f}{\left(\frac{v}{v + v_s}ight) f} = \frac{v + v_s}{v - v_s}$.Substituting the values:$\frac{f_{\max}}{f_{\min}} = \frac{330 + 30}{330 - 30} = \frac{360}{300} = 1.2$.

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