An airplane traveling at half the speed of sound
(v =  172 m/s) emits a sound of frequency 5.00 kHz. At
what frequency does a stationary listener hear the sound
(a) as the plane approaches? (b) after it passes?

Question

An airplane traveling at half the speed of sound
(v =  172 m/s) emits a sound of frequency 5.00 kHz. At
what frequency does a stationary listener hear the sound
(a) as the plane approaches? (b) after it passes?

rock_mit182 · Answer

@PsiSquared  you're the only one who can help , please

anonymous · Answer

For a stationary observer and an approaching source, the apparent frequency is given by:$$f _{O}=\frac{ v }{ v-v _{s} }f _{S}$$where fO is the frequency the observer hears; v is the speed of sound; vs is the speed of the source; and fS is the frequency emitted by the source.

For a stationary observer and a receding source, the apparent frequency is given by:$$f _{O}=\frac{ v }{ v+v _{S} }f _{S}$$

rock_mit182 · Answer

so i just have to plug the values in the right equation i guess, that's all ?

rock_mit182 · Answer

well, i have to go, tomorrow i will write the answer, if you want to verify. thanks for the explanation!

anonymous · Answer

No problem.