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A whistle you use to call your hunting dog has a frequency of 21 kHz, but your dog is ignoring it. You suspect the whistle may not be working, but you can't hear sounds above 20 kHz. To test it, you ask a friend to blow the whistle and hop on his moped. In which direction should he ride (toward or away from you) to know if the whistle is working? Explain in words or with a diagram

Answer :

Chlidonias

Answer:

Away from you

Explanation:

The whistle claims to be making a frequency of 21 kHz.

We need to decrease its frequency to make it audible.

Doppler effect explains the influence of motion of the source on the observed frequency. If the source is approaching the observed frequency will be higher than the real frequency. If the source is receding the observed frequency will be lower than the real frequency

For an approaching source

[tex]f_{observed}=f_{source}(\frac{v}{v+v_{source}} )[/tex]

For a receding source

[tex]f_{observed}=f_{source}(\frac{v}{v-v_{source}} )[/tex]

From the above fact we understand that the friend should ride away from us to decrease the frequency and make the whistle audible.

okpalawalter8

We have reduce frequency

21>20

Therefore

  • We move away at speed
  • v=16.19m/s

From the question we are told

  • A whistle you use to call your hunting dog has a frequency of 21 kHz, but your dog is ignoring it.
  • You suspect the whistle may not be working, but you can't hear sounds above 20 kHz.
  • To test it, you ask a friend to blow the whistle and hop on his moped.

Dopplers formula

Generally the equation for the dopplers formula is mathematically given as

[tex]f =\frac{ f0*(vs-v)}{vs}[/tex]

Therefore

[tex]20e3 = \frac{21e3*(340-v)}{340}[/tex]

v = 340/21

v=16.19m/s

Since

We have reduce frequency

21>20

Therefore

We move away

For more information on Dopplers visit

https://brainly.com/question/3004869

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