An ambulances siren emits a sound with a frequency of 600 hz when heard at rest.

Question

An ambulances siren emits a sound with a frequency of 600 hz when heard at rest. The ambulance is now in motion and its siren is heard by an observer in a moving car. Find the frequency of the siren as heard by the observer in each of the following three cases. <-40 m/s 20m/s -> 40 m/s -> 20 m/s -> 20 m/s -> 40 m/s -> An ambulances siren emits a sound with a frequency of 600 hz when heard at rest. The ambulance is now in motion and its siren is heard by an observer in a moving car. Find the frequency of the siren as heard by the observer in each of the following three cases. <-40 m/s 20m/s -> 40 m/s -> 20 m/s -> 20 m/s -> 40 m/s -> <-40 m/s 20m/s -> 40 m/s -> 20 m/s -> 20 m/s -> 40 m/s ->

Explanation / Answer

case 1)

velocity of Listener, VL = 20 m/s

Velosity of source, Vs = -40 m/s

velocity of sound, vo = 343 m/s

now Apply Doppler's effect,

frequency heard by the listener,

f' = f*(vo-VL)/(Vo - VS)

= 600*(343 - 20)/(343+40)

= 506 Hz <<<<<<---------Answer
case 2)

velocity of Listener, VL = 20 m/s

Velosity of source, Vs = 40 m/s

velocity of sound, vo = 343 m/s

now Apply Doppler's effect,

frequency heard by the listener,

f' = f*(vo-VL)/(Vo - VS)

= 600*(343 - 20)/(343-40)

= 639.6 Hz <<<<<<---------Answer

case 3)

velocity of Listener, VL = 20 m/s

Velosity of source, Vs = 40 m/s

velocity of sound, vo = 343 m/s

now Apply Doppler's effect,

frequency heard by the listener,

f' = f*(vo+VL)/(Vo - VS)

= 600*(343 + 20)/(343+40)

= 568.7 Hz <<<<<<---------Answer

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.