Doppler Definition and 749 Threads

Can anyone tell me what the doppler wavelength shift equation is? thanks

I am just beginning to learn about quantum mechanics and I have already come up with a question regarding it. I know that light is absorbed by an electron at once and I know about the doppler shift. Yet is light emitted at once, or gradually? If at once, how could the wavelength be shifted...

how much is a nebular line widened by the doppler broadening due to thermal motion of gas particles? What is the spectrographic resolution required to resolve the line? I do not understand how to solve this problem. I've been given specific numbers of an HII region. How do I find the...

Homework Statement I have a problem that asks to derive the doppler effect for the two different cases of a moving observer and a moving source. Homework Equations I should get f' = f*(v +/- vo)/(v +/- vs) as my general equation, where f' is the observed frequency and f is the...

I have a few questions concerning the Doppler Effect, I know what it is in terms of a moving object, and how speed effects fequency etc. but I'm more interested in the explantions. My actual knowledge of the two explanations is reasonably vague. The one I am interested in is the compression...

I am having a friendly argument with a friend. If a light source was moving towards a colored object at high speeds in a completely dark area, would the color shift due to the Doppler effect be doubled? Possible theories are no (which we agree is wrong) Yes (which may be right) Or simply...

A distant galaxy is moving away from us at a speed of 1.85x10^7m/s. Starting from the formula for the doppler shifted frequency, derive a formula for the change in wavelength and hence calculate the fractional redshift (λ'-λ₀)/λ₀ in the light from the galaxy. I'm pretty confused at the moment...

Homework Statement Ultrasound waves are used to measure blood-flow speeds. Suppose a device emits sound at 450 kHz, and the speed of sound in human tissue is taken to be 1540 m/s. What is the expected beat frequency if blood is flowing normally in large leg arteries at 3.0 cm/s directly away...

Homework Statement A source and an observer are each traveling at 0.52 times the speed of sound. The source emits sound waves at 1.2 kHz. (a) Find the observed frequency (in kHz) if the source and observer are moving toward each other. (b) Find the observed frequency (in Hz) if the...

Homework Statement A man is traveling on a bicycle at 14 m/s along a straight road that runs parallel to some railroad tracks. He hears the whistle of a train that is behind him. The frequency emitted by the train is 840 Hz, but the frequency the man hears is 778 Hz. Take the velocity of...

Doppler Effect...Ahhhh! Homework Statement A student in a parked car honks the horn, which has a `proper' frequency of 310.00 Hz. An observer in an approaching vehicle measures the frequency of the sound to be 342 Hz. Calculate the speed of the approaching vehicle. Use 340 m/s as the speed of...

Homework Statement The pitch of the sound from a racecar engine drops the musical interval of a fourth when it passes the spectators. This means the frequency of the sound after passing is 0.75 times what it was before. How fast is the racecar moving? 1. 61 m/s 2. 49 m/s 3. 72...

suppose i am moving in a train and at the same time playing a violin .Is the dopller effect/formulae applicable for me

A high speed train is traveling at a speed of 41 m/s when the engineer sounds the 416 Hz warning horn. The speed of sound is 345 m/s. What is the frequency of the sound as perceived by a person standing on at the crossing when the train is leaving? I used the equation: f0=fs/(1-vs/v) f0=416...

Homework Statement A 1.50-MHz sound wave travels through a pregnant woman’s abdomen and is reflected from the fetal heart wall of her unborn baby. The heart wall is moving toward the sound receiver as the heart beats. The reflected sound is then mixed with the transmitted sound, and 85 beats...

[SOLVED] Doppler Effect in Circular Motion Homework Statement A Physics professor annoys his students by tying a 500 Hz generator to a 60cm long string and whirling it around his head at 100 rpm. What are the highest and lowest frequencies heard by the students? Homework Equations...

BACKGROND: Myself and a number of others are doing a thing called Dynamic Soaring with our special purpose built radio controlled gliders. We are getting them going very fast; in the range of 300-320mph. We have verified a top speed of 309mph using radar guns but that is the highest that...

Homework Statement I am told that to a stationary observer, the lights infront of a spaceship has the wavelength = 480 nm when it arrives, and the lights in the back have wavelength 640 nm when the ship is moving away. Both lights (front and back) are the same. I have to find the wavelength...

A speeder is pulling directly away and increasing his distance from a police car that is moving at 23 m/s with respect to the ground. The radar gun in the police car emits an electromagnetic wave with a frequency of 6.0 109 Hz. The wave reflects from the speeder's car and returns to the police...

Hi, and thank you for your time to read this. I'm having a difficult time figuring out the answer to this question; Q: A porpoise swims toward a school of fish and emits a high pitched sound. The porpoise listens for the echo of its own squeak. I have to predict whether the observer will...

the formula of Doppler Effect f = fs(v + vd)/(v - vs) (v = speed of sound; d = detector; s = source) Simply from this formula, it can be seen that vd has differenct effect on the frequency receiver from vs. when vd or vs approaches the speed of sound, this difference is pronounced. make...

Defining the period measured by a moving observer relative to a stationary source as T=t(n)-t(n-1) where t(n) and t(n-1) represent the times when two successive wavecrests are received respectively, the theory of the Doppler Effect leads zero and negative periods in the case of sonic and...

Homework Statement A distant galaxy moving away from us at speed 1.85 *10^7 m/s. Calculate the fractional redshift (lambda'-lambda(0))/(lambda(0)) of the light from this galaxy. Homework Equations (lambda'-lambda(0))/(lambda(0))=lambda'/lambda(0)-1; f=(sqrt(1-beta)/sqrt(1+beta))*f(0)...

a Concept Question. Is there a Doppler Shift if the source and observer move in the same direction with the same velocity? Explain . Can someone drop their comments and ideas ..? please and thanks you.

Homework Statement An astronomer observes a hydrogen line in the spectrum of a star. The wavelength of hydrogen in the laboratory is 6.563 x 10-7m, but the wavelength in the star’s light is measured at 6.56186 x 10-7m. Which of the following explains this discrepancy? A) The star is...

DISCLAIMER: i may very well have exactly zero idea what I'm talking about. please feel free to berate me if i am way off base... so i know the doppler effect is normally used to determine an unknown radial velocity, but I'm assuming that if i know the velocity of the source, i can use the...

Homework Statement You're flying in an aircraft at 46 m/s. An eagle flies directly towards you at 11 m/s. Speeds are relative to ground. The eagle emits a cry at 3400 Hz, and the speed of sound is 330 m/s. What frequency do you hear? Homework Equations f_o = f_s\left(...

Homework Statement A parked car's alarm goes off, producing a sound at 961 Hz. As you drive toward, pass, and drive away from this parked car, you observe a frequency change of 98 Hz. At what speed are you driving? (Speed of sound is 343 m/s.) Homework Equations f_o = f_s\left(...

Homework Statement Hello, I'm researching about relativity and Doppler effect, most text and book gives the equation for it as (term with square root is on the numerator, and the term w/o is on the denominator) while on some text, has the reverse of the fraction part (which is the...

Homework Statement A radio played on a moving train has frequency of 85 Hz. A second radio played at train station is at rest. What is the beat frequency heard if train approaches the station at 10 m/s? Homework Equations f' = [f \ (1-vsource/vsound) I used this equation because the...

doppler effect / expanding universe . trouble uniting both concepts? Ok, I think I understand both; I just don't understand their relationship. As I understand the doppler effect, in short, its cause by the difference in velocity (movement through space). And as I understand the expansion...

I am playing with a small personal fan and I noticed that when the blades are moving at some frequency that "lines up" with my monitor refresh rate frequency, they appear blurry and stationary, but with altered shapes. Not only that, but certain edges of the blades are colored blue, while the...

A student runs toward the closed end of a hall while holding a vibrating tuning fork. The tuning fork is vibrating at 512Hz. The sound is reflected from the end of the hall back to the running student where 8.0 beats per second can be heard. Determind the speed of the student. i used the...

So the Red shift of extragalactic bodies means that they are moving away from us. And this effect is seen for all extra galactic objects minus the local group of galaxies. How then is it known that our local group is not the center of the universe? Wouldn't the fact that everything is moving...

Hi, I am a little confused about some aspects of sound waves. I was hoping to just check to see if I am on the right track. I have a problem where a guy is moving towards the great wall of china, with a air horn, emitting a constant frequency sound of 500Hz. The sounds is going to hit the...

I have a quick relativity question. Say an observer is moving at a relativistic velocity with respect to some light source that emits light at one particular frequency (the observer's path does not intersect the emitter). At the point of closest approach, will light from the emitter be Doppler...

Doppler effect homework problem help (still lost) Homework Statement A block with a speaker bolted to it is connected to a spring having spring constant k = 17.0 N/m, as in Figure P17.40. The total mass of the block and speaker is 44.00 kg, and the amplitude of this unit's motion is 0.475...

Homework Statement At the Indianapolis 500, you can measure the speed of cars just by listening to the difference in pitch of the engine noise between approaching and receding cars. Suppose the sound of a certain car drops by a factor of 1.50 as it goes by on the straightaway. How fast is it...

Homework Statement Is this true? the observed doppler shift for sound waves depends only on the relative motion of the source and the receiver. Homework Equations this is a concept-like question The Attempt at a Solution If no, doesn't mean, wind will affect the doppler effect?

Using a highly sensitive parabolic sound collector, Tom records the frequency of a tuning fork as it drops into the Grand Canyon. He drops the vibrating tuning fork from rest at t=0. He records a frequency of 1887.0 Hz at t=7.880 s. What is the natural frequency of the tuning fork? Use...

Assume: Take the speed of sound in air to be 343 m/s. A bat, moving at 5.9 m/s, is chasing a flying insect. The bat emits a 46 kHz chirp and receives back an echo at 46.26 kHz. At what speed is the bat gaining on its prey? Answer in units of m/s. I tried this: f=initial frequency...

Einstein in his "On the electrodynamics of moving bodies" (1905) starts the derivation of the Doppler shift formula by stating: In the system K, very far from the origin of coordinates let there be a sourcce of electromagnetic waves..." . Taking into account his advise "never stop thinking" we...

Hey guys...or ladies...um...just wondering what I hav done wrong for the following Q, it is an online Q i am doing and it tells me my answer is incorrect? Q) "A car alarm is emitting sound waves of frequency 520 Hz. You are on a motorcycle, traveling directly away from the car." "How...

In relativistic doppler shift, the energy of the photon is increasing och decreasing, due to realative motion of observer vs emitter. Let say that the photon is redshiftet, does any energy dissapear? :rolleyes:

I know that in spectroscopic Binaries, you can observe wavelength shifts in each star. But how do you determine the total radial velocity of this system alltogether, and how do you find each star's radial velocity?

Homework Statement Suppose that a police car on the highway is moving to the right at 28 m/s, while a speeder is coming up from almost directly behind at a speed of 34 m/s, both speeds being with respect to the ground. The police officer aims a radar gun at the speeder. Assume that the...

I was playing around with a thought experiment where an observer is moving towards a light source at a speed infinitesimally less than C and it seems like, for any given wavelength, the maximum possible Doppler shift is 1/2. for example near infrared light with a wavelength of 800 nm would be...

I have a question regarding the doppler effect and frequency: You (a stationary observer) are standing by the railroad tracks and hear a frequency of 1000 Hz as the train approaches... as the train goes away, the frequency changes to 800 Hz. Knowing that the speed of sound is 340 m/s, how...

A train is traveling at 30.0 m/s relative to the ground in still air. The frequency of the note emitted by the train whistle is 262 Hz. a. What frequency (fapproach) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first...

I would need a pointer to a mainstream treatment of the general relativistic Doppler effect when source and receiver are accelerated wrt each other. Book/paper/wiki . No crank papers , please (i.e. no Apeiron and such). Thank you.