Doppler effect Definition and 513 Threads

This question refers to Doppler Effects observed in circular motion (at non relativistic speeds, so ##v\ll c##, ignoring transversal Doppler shifts). Suppose there is a source emitting a frequency, ##f_s##. An observer at the center will experience no shift in observed frequency (##f_r##). As...

The wavelength of the sent waves is ##\lambda = \frac{c-v}{f_0}##. Reflected waves will maintain this wavelength. For the bat, the reflected wave's speed is ##c+v##, so relative to the bat, its frequency is ##\frac{c+v}{\lambda}=f_0\frac{c+v}{c-v}##. Since the difference between frequencies of...

My answer is (A) but the correct answer is (B). My attempt: $$f_2=\frac{v\pm v_o}{v\pm v_s}f_1$$ $$=\frac{v+0.1v}{v}f_o$$ $$=1.1f_o$$ If we consider the observer to move pass through the sound source and now is moving away from the stationary source, then: $$f_2=\frac{v-0.1v}{v}f_o$$...

For this, Does someone please know whether they assume for the equation highlighted that ##\frac{v}{f} ≥ \frac{v_S}{f}## since otherwise the wavelength would be negative (which I assume is impossible)? Many thanks!

Hi, I am looking for some sound clip examples of the doppler effect for some specific questions. Specifically I would like to find a single tone/horn recorded in the three different ways: 1. Not moving at all 2. Moving past the recorder at a slower speed 3. Moving past the recorder at a higher...

Hi. I need help with part a). I calculated the wavelength of the source by using the formula f_0 = v_phasefront / λ and got λ = (343 m/s) / (520 Hz) = 0.6596 m. And then I set up an equation for the velocity of the source v(t) = a*t (with v(t = 0 )= 0 m/s) and s(t) = 1/2 * at^2 + s_0. But I...

I am trying to understand a case of doppler shift if I have two satellite circling the earth with different velocities but the same direction and with different altitudes as well. How I will be able to figure out the doppler shift in three dimension between the two satellite if one of the...

I'm a highschool student learning about astrophysics, and I'm trying to understand this paper by Dr. Sophia Cisneros because I find it interesting and I want to do an informational interview. The problem is, I just have really bad reading comprehension, especially with all the scientific jargon...

hello everyone How is the sound Doppler effect formula in the case where the movement of the source and the observer is at an angle?

Is the doppler effect on electromagnetic waves receive by cell phone in fast car and so somebody talk with cell phone in fast car view this effect

Hello everyone! I'm watching a Walter Lewin lecture and it seems to me at least that he is dividing maximum frequency of the sound by sound frequency of the transmitter to derive velocity of the transmitter, does this work? It seems that quantity would be dimensionless and velocity obviously...

Hi, I know the usual formula for both moving source and receiver in a static medium (from wiki): Is ir correct? What about when the medium is moving too? I can't seem to find an answer, and worst, I'm finding contradicting ones. For example, when the source and the receiver are moving at the...

I have read about doppler effect in acoustics so i searched for the relation ship between wavelength of wave produced by linear movement of body and its momentum along with other dependent variables such as density of fluid (leaving acoustics for a second) and temperature but souldn't find a...

Can you derive the formula for frequency observed from doppler effect with stationary person and moving sound source away from the person like this: ##v_t = v + v_s## where ##v_t## is the total velocity observed by stationary person from moving sound, v is velocity of sound and ##v_s## is...

Hi all, My question is about Doppler redshifts, but I'm going to mention cosmological redshifts first because I'm a lay person as far as cosmology's concerned (I'm an amateur astronomer and did a few introductory astrophysics/cosmology courses at university, but my degree focus was planetary...

Hey guys! I will pass an illustrated problem, below. - We know that the solar rays that reach the Moon and Earth are practically parallel; - We know that the lunar orbit with respect to Earth lasts 27.322 days or 2,360,621 seconds; - We know that the lunar orbit with respect to the Earth is...

Does time dilation in Special Relativity relate to the Doppler effect? If you move near the speed of light you experience time differently and the sound is stretched. Are these similar phenomenon?

Hey everyone, if I were to view a shining person rotating near a black hole at near the speed of light there would be 2 kinds of redshifts: gravitational redshift and relativistic doppler effect redshift. Right? But, say at some point, the person is traveling towards me, then the doppler effect...

If two cars are driving side by side at the same speed, their relative speed is zero but do they nonetheless perceive a sound Doppler effect from the other car's siren because of the apparent headwind generated by their speed?

From what I understand, the anomalous Doppler effect can occur when a charged particle moves through a medium faster than light would move through that medium; however in the paper, The Doppler Effect in a Warm Uniaxial Plasma, it mentions that this effect can occur when a dipole moves faster...

I found the observed frequency from the energy. Then I used the receding Doppler shift formula to find, the source frequency but after that when i tried to use the Rydberg equation I got a value for the energy level less than one. and I'm pretty sure my work is right, any help is greatly...

Hi there, here's the problem: There's a sound, with a certain frequency coming, from a source. Both the listener and the source are fixed in a inertial reference frame. But there's wind blowing from the source to the listener. Now, this situation isn't the same as the listener chasing the...

I'm struggling a lot with this problem on the Doppler effect. I understand the first step which is to treat the bat as the source of the emitted sound, giving And the second to treat the bat now as the observer, but instead of using f_b on the left the solution involves setting both...

AM/FM radio stations, cell phone towers transmit signals at certain frequencies. How can the frequency of a signal change depedning on whether the receiver is moving towards or away from the source? I thought that the frequency of an electromagnatic wave is determined at the source (the energy...

I am assuming that B is a stationary observer here. For the first part of the trip, using the formula, rocket A is approaching B at velocity $$v_A$$ =0.6 c. The length that A travels is $$L_A = v_A t_1 $$ where $$t_1 = $$ 6 hrs. For the first part of the trip, B is receiving signals at a rate...

A type of star that usually emits light at a frequency of 6.00 × 10^14 Hz appears to emit light at a frequency of 6.01 × 10^14 Hz. Calculate how fast the star is moving, and if it moving towards us or away from us.

I'm trying to understand the Energy-Momentum relativistic relationships for a light particles. It is commonly said that the Energy of a photon depends on the observer by the relationship ## E = - \mathbf{p} \cdot \mathbf{u}## where p is the 4-momentum of the source emitting light particles and u...

The Doppler effect of light corresponds to the classical Doppler effect corrected by time dilation, but the first one is obtained with classical velocity additions (c+v at the front of the source and c-v at the back) whereas velocity addition of special relativity gives c at the front and c at...

Summary:: Two speakers A and B are at rest, and a listener L stays on the line that connects the two speakers (see picture). The speakers have almost the same frequency. Assume that the speed of sound in air is 340 m/s. When the listener is at rest, he/she hears beats with frequency 6 Hz. The...

Being honest, I couldn't do any works for this problem... (even couldn't start...) Does anyone can help me for solving this...? Thank you!

https://www.asi.edu.au/wp-content/uploads/2015/03/PhysicsASOE2014solutions.pdf q 14b) i) Assuming that the planet is rotating at a constant rate, shouldn't the distribution be even across all wavelengths, or do I have something very wrong with my model. I take the graph as the summation of...

I am trying to figure out why the relativity don't get in the doppler effect, that is, why can't we apply the "galileo transformations" in doppler effect? OBS: i am not saying about doppler effect relativistic (using Lorentz transformation) In another words, i am moving in direction to a source...

If the source is at ##(t,0)## in ##S## and the receiver is at ##(t',0)## in ##S'## which moves at ##\beta_x## w.r.t. ##S##, then by considering two crests at ##(0,0)## and ##(T_s, 0)## in the source frame ##S## and transforming these events into ##S'## we can derive that ##\lambda_{r} =...

I found it confusing since there is only "mutual" speed of both aircrafts and hence I do not know how to correctly put it into the common Dopplers formula...

Looking for a beginners explanation to the following question: How is Doppler effect separated from the original spectrum of light emanating from a moving body (in astronomy or other physics branches)? If the question does not make sense, here is the reasoning to ask it: If a certain color is...

**I realize some of my inline math delimiters '\(' and '\)' are not acting on the text for some reason, and it looks clunky. I spend 20-30 minutes trying to understand why this is, but I can't. My limited LaTeX experience is in Overleaf, and these delimiters work fine in that compiler. My...

I had many attempts on trying to solve this one, but I got always stuck in the problem-solving part: how do I manage to find the source-speed from the Doppler formula, in an analytical way, and then reach to the result-formula? Anyway, I'm pretty sure the only formula needed to solve this...

I have a few questions about redshift. First off, is it believed that the redshift of a galaxy is completely due to the Doppler effect or could something else be contributing to the redshift. And second, do the values we receive for the redshift of a galaxy vary slightly depending on are...

Just a random thought. The following may all be wrong:Einstein's a relative predicted the existence of gravity waves/gravitons right? With are supposed to propagate at the speed of light? If thus the speed of gravity is constant, wouldn't we experience a doppler effect with the gravity waves for...

Hello,I Have Some Wonders About Doppler Affect.As We All Know , The Other Galaxies Around Us Have Millions Of Starts , And those Starts emits lights , Those Lights Will Reach Us After Running So Very Far Disrtance .If We Take For Instance , The Farest Galaxy From Us ( About 15 000 000 Millhion...

Can somebody help clarify something for me?In 1887, Albert Michelson and Edward Morley conducted an experiment where they compared the speed of light in two beams at right angles to each other. As the earth traveled around the sun in the course of year, no discrepancy in the two beams was...

This problem is not new. It's not my idea. Someone else has posted it here before, and there was a discussion about it. There was a final post which seemed to answer the question for good.Well I've thought about it again, and now I think that answer was wrong. OK, here goes:You have a radio...

A motorist goes through a red light but when caught, he calimed he saw the green light(lambda=540 nm) and not red(lambda=620 nm) due to the Doppler Effect.(i.e. because of the speed with which he was travelling through the intersection) The judge accepts his claim and fines him for speeding at...

Hey all. Question 1: Let's say we start with a red wavelength photon, that is absorbed by an atom and raises the atom to an excited state. The atom is then accelerated. After reaching a high velocity (say 0.1c), the photon is emitted. I would have thought that the energy of the emitted photon...

Summary: I have a question on cosmological redshift which I have just learned about from Sean Carroll. After calculating it for an expanding universe he does a thought experiment to show that it is different to Doppler redshift which would be detected if two galaxies were flying away from each...

My answer on this question for now is that producing a waves in the medium is an event which is basically must be invariant in the any of frame of references. For an example: a brick is freely falling, then the brick suddenly splinted into two pieces — no matter from which frame will we observe...

Pretending the siren is at rest in air: Wavelength = velocity/frequence --> (343 m/s) / 10,000 Hz = .0343m. I don't believe this is the correct way to go about solving the problem, since the vehicle is moving at the start and the siren is not at rest.

If I and the light source are both moving toward one another, I see light blueshifted. What if I'm at rest and the source moving towards me?

I don't know what is wrong i think when bat gets sound f' = f×(c+v/c) when audience hears f''=f'×(c/c-v) f''=f×1.059 but it is wrong TT

Kindly don't delete the post again, I am a teacher. The question above mentioned came in Board Exams 2 years ago in our Country. We the group of teachers tried to solve but we found that the problems misses the required information to be solved. The data still seems to be the case of Doppler's...