Question #f55c0

1 Answer
May 16, 2017

"Please examine carefully the animation."Please examine carefully the animation.
"The sound emitted by the ambulance is perceived differently"The sound emitted by the ambulance is perceived differently
"by the observers."by the observers.
v_S=25.19" "m/svS=25.19 ms

Explanation:

enter image source here

v:"speed of wave"v:speed of wave
f_A:"The frequency of the sound heard by the observer A."fA:The frequency of the sound heard by the observer A.
f_B:"The frequency of the sound heard by the observer B."fB:The frequency of the sound heard by the observer B.
v_S:"speed of source"vS:speed of source
f_S:"source frequency"fS:source frequency

"frequency for the observer A: "frequency for the observer A:

f_A=f_S(v/(v+v_S))fA=fS(vv+vS)

"frequency for the observer B: "frequency for the observer B:

f_B=f_S(v/(v-v_S))fB=fS(vvvS)

f_B=f_A+0.16 f_A fB=fA+0.16fA

cancel(f_S)(v/(v-v_S))=cancel(f_S)(v/(v+v_S))+0.16(cancel(f_S)(v/(v+v_S)))

(v/(v-v_S))=(v/(v+v_S))+0.16(v/(v+v_S))

(cancel(v)/(v-v_S))=(cancel(v)/(v+v_S))(1+0.16)

1/(v-v_S)=(1.16)/(v+v_S)

1.16v-1.16v_S=v+v_S

1.16v-v=v_S+1.16v_S

0.16v=2.16v_S

v=340 m/s

0.16*340=2.16*v_S

v_S=(0.16*340)/(2.16)

v_S=25.19" "m/s