172986 An observer and a source emitting sound of frequency $120 \mathrm{~Hz}$ are on the $\mathrm{X}$-axis. The observer is stationary while the source of sound is in motion given by the equation $x=3 \sin \omega t(x$ is in metres and $t$ is in seconds). If the difference between the maximum and minimum frequencies of the sound observed by the observers is $22 \mathrm{~Hz}$, then the value of $\omega$ is (speed of sound in air $=330 \mathrm{~ms}^{-1}$ )

172987 A small source of sound vibrating at a frequency $500 \mathrm{~Hz}$ is rotated along a circle of radius $\frac{100}{\pi} \mathrm{cm}$ at a constant angular speed of 5 revolutions per second. The minimum and maximum frequency of the sound observed by a listener situation in the plane of the circle is (speed of sound is $332 \mathrm{~ms}^{-1}$ ).

172991 When a train is approaching the stationary observer, the apparent frequency of the whistle of the train is $f_{1}$ and when the train is moving away from the observer, the apparent frequency in $f_{2}$. The frequency of the whistle noticed by the observer when he moves with the train is

172992 A train moves towards a stationary observer with speed $34 \mathrm{~ms}^{-1}$. The train sounds a whistle and its frequency registered by the observer is $f_{1}$. If the speed of the train is reduced to $17 \mathrm{~ms}^{-1}$ the frequency registered is $f_{2}$. If the speed of sound is $340 \mathrm{~ms}^{-1}$, then the ratio $f_{1} / f_{2}$ is:

172986 An observer and a source emitting sound of frequency $120 \mathrm{~Hz}$ are on the $\mathrm{X}$-axis. The observer is stationary while the source of sound is in motion given by the equation $x=3 \sin \omega t(x$ is in metres and $t$ is in seconds). If the difference between the maximum and minimum frequencies of the sound observed by the observers is $22 \mathrm{~Hz}$, then the value of $\omega$ is (speed of sound in air $=330 \mathrm{~ms}^{-1}$ )

172987 A small source of sound vibrating at a frequency $500 \mathrm{~Hz}$ is rotated along a circle of radius $\frac{100}{\pi} \mathrm{cm}$ at a constant angular speed of 5 revolutions per second. The minimum and maximum frequency of the sound observed by a listener situation in the plane of the circle is (speed of sound is $332 \mathrm{~ms}^{-1}$ ).

172991 When a train is approaching the stationary observer, the apparent frequency of the whistle of the train is $f_{1}$ and when the train is moving away from the observer, the apparent frequency in $f_{2}$. The frequency of the whistle noticed by the observer when he moves with the train is

172992 A train moves towards a stationary observer with speed $34 \mathrm{~ms}^{-1}$. The train sounds a whistle and its frequency registered by the observer is $f_{1}$. If the speed of the train is reduced to $17 \mathrm{~ms}^{-1}$ the frequency registered is $f_{2}$. If the speed of sound is $340 \mathrm{~ms}^{-1}$, then the ratio $f_{1} / f_{2}$ is:

172986 An observer and a source emitting sound of frequency $120 \mathrm{~Hz}$ are on the $\mathrm{X}$-axis. The observer is stationary while the source of sound is in motion given by the equation $x=3 \sin \omega t(x$ is in metres and $t$ is in seconds). If the difference between the maximum and minimum frequencies of the sound observed by the observers is $22 \mathrm{~Hz}$, then the value of $\omega$ is (speed of sound in air $=330 \mathrm{~ms}^{-1}$ )

172987 A small source of sound vibrating at a frequency $500 \mathrm{~Hz}$ is rotated along a circle of radius $\frac{100}{\pi} \mathrm{cm}$ at a constant angular speed of 5 revolutions per second. The minimum and maximum frequency of the sound observed by a listener situation in the plane of the circle is (speed of sound is $332 \mathrm{~ms}^{-1}$ ).

172991 When a train is approaching the stationary observer, the apparent frequency of the whistle of the train is $f_{1}$ and when the train is moving away from the observer, the apparent frequency in $f_{2}$. The frequency of the whistle noticed by the observer when he moves with the train is

172992 A train moves towards a stationary observer with speed $34 \mathrm{~ms}^{-1}$. The train sounds a whistle and its frequency registered by the observer is $f_{1}$. If the speed of the train is reduced to $17 \mathrm{~ms}^{-1}$ the frequency registered is $f_{2}$. If the speed of sound is $340 \mathrm{~ms}^{-1}$, then the ratio $f_{1} / f_{2}$ is:

172986 An observer and a source emitting sound of frequency $120 \mathrm{~Hz}$ are on the $\mathrm{X}$-axis. The observer is stationary while the source of sound is in motion given by the equation $x=3 \sin \omega t(x$ is in metres and $t$ is in seconds). If the difference between the maximum and minimum frequencies of the sound observed by the observers is $22 \mathrm{~Hz}$, then the value of $\omega$ is (speed of sound in air $=330 \mathrm{~ms}^{-1}$ )

172987 A small source of sound vibrating at a frequency $500 \mathrm{~Hz}$ is rotated along a circle of radius $\frac{100}{\pi} \mathrm{cm}$ at a constant angular speed of 5 revolutions per second. The minimum and maximum frequency of the sound observed by a listener situation in the plane of the circle is (speed of sound is $332 \mathrm{~ms}^{-1}$ ).

172991 When a train is approaching the stationary observer, the apparent frequency of the whistle of the train is $f_{1}$ and when the train is moving away from the observer, the apparent frequency in $f_{2}$. The frequency of the whistle noticed by the observer when he moves with the train is

172992 A train moves towards a stationary observer with speed $34 \mathrm{~ms}^{-1}$. The train sounds a whistle and its frequency registered by the observer is $f_{1}$. If the speed of the train is reduced to $17 \mathrm{~ms}^{-1}$ the frequency registered is $f_{2}$. If the speed of sound is $340 \mathrm{~ms}^{-1}$, then the ratio $f_{1} / f_{2}$ is: