The Doppler effect refers to change in the observed frequency of a wave if the observer and source are in relative motion.
Questions tagged [doppler-effect]
534 questions
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Why isn't the Doppler effect (for sound waves) symmetric with respect to source and receiver?
The Doppler effect formula is $$f = \frac{(v\pm v_r)}{(v\mp v_s)}f_0$$ where $f$ and $f_0$ are the observed and emitted frequency, respectively, and $v, v_r$ and $v_s$ the speed of the waves, receiver and source, respectively (all relative to the…
Javi
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Doppler Effect: What is formula for Rate of Change of Period observed by accelerating receiver?
(I have looked at other questions relating to Doppler Effect with acceleration but none seem to provide the formula in question.)
Edit: I wish to avoid using the Einsteinian relativity model. So consider the pulses as sound pulses moving in a body…
steveOw
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Doppler effect from an accelerating frame of reference
The standard equation for the doppler effect from a frame of reference with constant velocity is
$f_0$ initial frequency;
$v$ is the velocity of waves in the medium;
$v_r$ is the velocity of the receiver relative to the medium;
$v_s$ is the…
metzgeer
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Anti-symmetry in Doppler Effect
I know the formula $\nu = \nu_{0}\frac{v + v_{o}}{v - v_{s}}$ for the Doppler Effect and saw that it gives different results in the cases where:
1- The source is stationary and the observer moves towards the source with speed $v$, and
2- The…
Okan Atiker
- 31
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Difference between Doppler effect and relativistic Doppler effect?
When the source of a sound wave is moving in the direction of the sound wave it is a different scenario than if the receiver of the sound wave is moving in the direction where the sound waves are coming from. Why is this not the case in the…
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What is meaning of negative frequency got from Doppler equation?
If a observer is moving away from a stationary sound source with a velocity V' then observed frequency is (1-V'/v)f where v is the speed of sound and f is the frequency observed when at rest. Now if V'>v what will happen actually? What is the…
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Doppler effect contradiction when counting wave fronts
For concreteness, let's take a source moving away from a stationary observer.
The observed frequency will be less than the emitted frequency, so for any given time interval, the observer will count less incoming peaks than the source counts…
1sadtrombone
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Doppler shift and relative velocity
I have come across Doppler shift equation. If we consider the source to be moving toward the observer at a speed $V$ and observer moving toward the source with a speed $U$, for the calculation of the apparent frequency, can't we think of the…
Tejesh Atr
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With respect to the doppler effect, are pitch changes sudden or gradual?
Before reading the below content, it is important to read the final note at the bottom first.
Take this excerpt from Wikipedia regarding the Doppler effect: if the siren approached the observer directly, the pitch would remain constant until the…
Michael Lee
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Doppler shift equation results in inconsistencies
The non-Relativistic Doppler shift equation is $f = \left( \frac{c + v_\text{r}}{c + v_\text{s}} \right) f_0 $ where c is the speed of the medium (346.4 m/s for sound at 25 C temperature). I tried calculating the Doppler shift for the case when the…
user120404
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Doppler effect via reflection
Suppose a police car is standing by a wall. The siren light is rotating and it will hit the wall and reflect back to the car. Does the reflected light show a Doppler effect?
Maesumi
- 264
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2 answers
Dopler Shift for Reflected Sound Waves
If a car was going at near mach-1 speed heading towards a wall and honked its horn. What frequency would the driver measure the reflected sound wave? I trying to think about this reasonably, but the answer I get is somewhat not what I initially…
Novice C
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Relativistic Doppler Effect compared with Classical Doppler Effect
Looking at the classical Doppler effect there is one generalized equation, and they have a velocity of source, and observer.
In the relativistic version, there is only one velocity taken into account, and, in my book, there are two separate…
user24082
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2 answers
If the only way to observe a tone generating object is by listening, can a distinction be made whether the object, the listener, or the air is moving?
Although most commonly associated with a moving object emitting a tone (like a car or train), a sound may also be doppler shifted if the listener is moving or (even less obvious) if the air medium is moving between a stationary tone and stationary…
Hal McKinney
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Doppler effect when source moves with observer
I have a doubt concerning a scenario of Doppler Effect wherein the source and observer are on the same relative frame.
A car is moving towards a stationary observer with speed 10 m/s. The horn has a frequency of 640 Hz. What is the frequency of the…
Safdar Faisal
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