A whistle emitting a loud sound of frequency | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(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

Vedclass · Accepted Answer

$1.2$

Vedclass · Answer

(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:$\frac{f_{\max}}{f_{\min}} = \frac{330 + 30}{330 - 30} = \frac{360}{300} = 1.2$.

Similar Questions

$A$ musician using an open flute of length $50\,cm$ produces second harmonic sound waves. $A$ person runs towards the musician from another end of a hall at a speed of $10\,km/h.$ If the wave speed is $330\,m/s,$ the frequency heard by the running person shall be close to...... $Hz$

$A$ car sounding its horn at $480\,Hz$ moves towards a high wall at a speed of $20\,m/s$. If the speed of sound is $340\,m/s,$ the frequency of the reflected sound heard by the passenger sitting in the car will be the nearest to ..... $Hz$.

$A$ source of sound is moving with a constant velocity of $20\, m/s$ emitting a note of frequency $1000\, Hz.$ The ratio of frequencies observed by a stationary observer while the source is approaching him and after it crosses him will be (Speed of sound $v = 340\, m/s$).

Vedclass Test Series

Exam Paper Generator

Online Exam Module