Question

Question #f55c0

Answer 1

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

Explanation:

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

`"frequency for the observer A: "`

`f_A=f_S(v/(v+v_S))`

`"frequency for the observer B: "`

`f_B=f_S(v/(v-v_S))`

`f_B=f_A+0.16 f_A`

`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`