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Delicious77 [7]

2 years ago

7

An ambulance is driving towards the hospital at a velocity 108 km/h and emitting a steady 798-Hz sound from its siren. The sound

reflects off the front of the hospital and is received by the same ambulance. In addition to it's own siren, the ambulance hears a shifted tone from the reflection at what frequency? The speed of sound on this day is 343 m/s. a. 1.06e+3Hz b. 855Hz c. 850Hz d. 1.08e+3Hz e. 950 Hz

1 answer:

slava [35]2 years ago

5 0

To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is a physical phenomenon where an apparent change in wave frequency is presented by a sound source with respect to its observer when that same source is in motion. Mathematically it can be described as

$f_d= f_s \frac{(v+v_d)}{(v-v_s)}$

The meaning of each of these variables is,

$v_d=$ Velocity of detector

$f_s$ =Frequency of wave emitted by source

$v_s=$ Velocity of source

v=Velocity of sound wave

$f_d$ =Frequency received by detector

Replacing we have that,

$f_d = 798(\frac{(343+30)}{(343-30)})$

$f_d=950 Hz$

Therefore the correct option is e. 950Hz

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Complete Question

The complete question is shown on the first uploaded image

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a

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