A siren emitting a sound of frequency $$800$$ Hz moves away from an observer towards a cliff at a speed $$of15$$ m $$s-1$$ . Then, the frequency of sound that the observer hears in the echo reflected from the cliff is? $$(The$$ Velocity of Sound in $$air=330$$ m $$s-1$$

Question

A siren emitting a sound of frequency $$800$$ Hz moves away from an observer towards a cliff at a speed $$of15$$ m $$s-1$$ . Then, the frequency of sound that the observer hears in the echo reflected from the cliff is? $$(The$$ Velocity of Sound in $$air=330$$ m $$s-1$$

Infinity Learn · Accepted Answer

Here, frequency of sound emitted by siren, $$v0=800$$ Hz Speed of source, $$vs=15$$ m $$s-1$$ Speed of sound in air, $$v=330$$ m $$s-1Apparent$$ frequency of sound at the cliff $$=$$ frequency heard by $$observer=v$$ Using Doppler's effect of sound $$v=vv-vsv0=330330-15$$×$$800=330315$$×$$800=838.09$$ Hz≈$$838$$ Hz

A siren emitting a sound of frequency $800 Hz$ moves away from an observer towards a cliff at a speed of $15 m s^{- 1}$ . Then, the frequency of sound that the observer hears in the echo reflected from the cliff is? (The Velocity of Sound in air $= 330 m s^{- 1})$

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A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of15 m s-1 . Then, the frequency of sound that the observer hears in the echo reflected from the cliff is? (The Velocity of Sound in air=330 m s-1

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Ready to Test Your Skills?

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A siren emitting a sound of frequency $800 Hz$ moves away from an observer towards a cliff at a speed of $15 m s^{- 1}$ . Then, the frequency of sound that the observer hears in the echo reflected from the cliff is? (The Velocity of Sound in air $= 330 m s^{- 1})$