Mapoob sapling leaning u are walking along a small country road one foggy mornin

Question

Mapoob sapling leaning u are walking along a small country road one foggy morning and come to an intersection. While you are rossing, you hear an ambulance siren. As a paramedic, you know that the siren sounds at a frequency of 6.67 kHz. But, as an amateur musician with perfect pitch, you can tell that the frequency you are hearing is actually 6.01 kHz. Is the ambulance moving toward or away from you? O toward away At what speed is the ambulance traveling? Number -81.04 mph There is additional feedback available! View this feedback by clicking on the bottom divider bar. Click on the divider bar again to hide the additional feedback Clase Previous #Try Again O Next Exit Explanation

Explanation / Answer

Doppler's effect:
f' = {(c+Vo)/(c-Vs)}*f
Here: Vo is speed of observer along the line joining them
Vs is speed of source along the line joining them
c is speed of sound in air = 767.27 mph

here:
Vo= 0
f' = 6.01 kHz
f = 6.67 kHz

The above formula for Vo=0 becomes
f' = {(c)/(c-Vs)}*f
Here f' has decreased
So, Vs must be negative.
So source is moving away.

f' = {(c)/(c-Vs)}*f
6.01 ={(767.27)/(767.27-Vs)}*6.67
(767.27)/(767.27-Vs) = 0.901
767.27 = 691.35 -0.901Vs
Vs= -84.26 mph
Here negative sign shows moving away

Answers:
away
84.26 mph

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