A source of sound is moving with constant velocity of 20 m/s emitting a note of frequency 1000 Hz. The ratio of frequencies observed by a stationary observer while the source is approaching him and after it crosses him will be
(Speed of sound v = 340 m/s)

Question

A source of sound is moving with constant velocity of 20 m/s emitting a note of frequency 1000 Hz. The ratio of frequencies observed by a stationary observer while the source is approaching him and after it crosses him will be

(Speed of sound v = 340 m/s)

Infinity Learn · Accepted Answer

When source is approaching the observer, the frequency $$heardna=vv$$−vS×$$n=340340$$−$$20$$×$$1000=1063HzWhen$$ source is receding, the frequency heard $$nr=vv+vS$$×$$n=340340+20$$×$$1000=944$$ ⇒na:$$nr=9$$:$$8Short$$ tricks :  $$nanr=v+vSv$$−$$vS=340+20340$$−$$20=98$$.

A source of sound is moving with constant velocity of 20 m/s emitting a note of frequency 1000 Hz. The ratio of frequencies observed by a stationary observer while the source is approaching him and after it crosses him will be
(Speed of sound v = 340 m/s)

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A source of sound is moving with constant velocity of 20 m/s emitting a note of frequency 1000 Hz. The ratio of frequencies observed by a stationary observer while the source is approaching him and after it crosses him will be(Speed of sound v = 340 m/s)

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Ready to Test Your Skills?

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A source of sound is moving with constant velocity of 20 m/s emitting a note of frequency 1000 Hz. The ratio of frequencies observed by a stationary observer while the source is approaching him and after it crosses him will be
(Speed of sound v = 340 m/s)