Doppler Definition and 749 Threads

How can we apply the doppler effect when the source of sound is coming towards us at supersonic speeds?Is there a mathematical method for it?

Why is it that the extent of the doppler effect on sound depends on whether, for example, you are moving towards the source or the source is moving towards you? Why does this not happen for light?

I have been working on this problem for over a half hour. I'm not sure where I'm going wrong with it. If anyone could help me out I would really appreciate it. You stand by the railroad tracks as a train passes by. You hear a 1000 Hz frequency when the train approaches, which changes to...

In "Concepts of modern physics 6/e by arthur beiser", there's a paragraph on pg11 explaining th effec on the observer moving perpendicular to a line between him and the light source. Why is the proper time between ticks to=1/vo?

If you are driving in a car up to a set of trafic lights that are red, how fast would you need to be going to make the lights appear green? (take the velocity of light to be 3x10^8 ms-1 and the wavelength of red light to be 620nm and the wavelength of green light to be 540nm) Ive calculated...

Suppose a sound source S is moving towards a stationary wall and that a listener L1 is moving with the sound source. Describe in a few lines why the reflected sound heard by the listener L1 is Doppler-shifted by about twice the amount that a second listener L2 would hear standing by the wall...

Hi, I am sort of a new to physics. So far I've only been doing motion, up to the formula for average power. However I was reading something in Earth Science as I was going to help someone study for their regents test, you know how school is almost over and all. Then I read about the Doppler...

Hello, There's a problem with the doppler efect that I don't understand. When a object runs at a velocity a little minor than velocity of sound, appears in front of the emisor a group of high frecuence, that in simulators (applets) is increasing in time. This wave, is like a physical...

I don't know how to understand doppler shifts and yet conserve energy. Consider a red photon is emitted by a torch. This photon is let free to travel through space. Any observer at rest relative to the torch (which by now may be millions of miles away) will see it as a red photon...

hey just wondering about the doppler effect and how it is used in meterology, law enforcment and astronomy. I know for law enforcment they use it in radar guns, and astronomy i think for finding the distance of planets? Any other ways it used? and also how is ultra sound used in medicine...

generic redshift is characterised (defined) by z = (L-L0)/L0 where L is the wavelength at time of absorption (detection), and L0 was the wavelength at time of emission. for Doppler redshift z = v/c for small (non-relativistic) values of v. assuming the universe is expanding, I've read...

A block with a speaker bolted to it is connected to a spring having spring constant k = 21.0 N/m, as in Figure P17.40. The total mass of the block and speaker is 46.00 kg, and the amplitude of this unit's motion is 0.475 m. Assume that the speed of sound is 343 m/s. Figure P17.40...

Hello. I have a question on Doppler effect. When the wave has the same velocity that the emisor, u have this: f= \frac {\partial {(Vs-Vo)}} {\partial {(Vs-Ve)}} f' In this case, Vs=Ve, f=infinite?

I am to measure the rotational velocity of Io relative to Jupiter, and will do so using a spectrograph. I will measure the frequency change of a specific mineral emmision band in the spectra, and then check how much it has shifted from its original wavelenght with a table. Then I use the...

uestion is How does the second order term in teh relativistic doppler shift (v/c)^2 compare to the total classical Doppler Shift for the observer receeding away from the source? now the doppler shift (relativistic) is \Delta f = |f_{0} (1-\sqrt{\frac{1-\beta}{1+\beta}})| for the...

A lithium atom with initial velocity of 1000m/s (x hat direction) will be deflected into a positron cloud by a laser of wavelength 670nm. The laser beam is 1mm high and 15cm long and has an average power of 1mW. As the atoms absorbs each pohoton it is deflected in the yhat direction by a small...

In class we were explained that if the source moves toward the stationary observer f' = f_{0} \frac{v}{v-v_{s}} where f0 is then aturla frequency of the wave, v is hte speed of the wave, and vs is the speed of the source and f' = f_{0} \frac{v_{rel}+v}{v} where vrel is the speed of...

I know which equations to use for solving Doppler Effect problems, so figuring out which is the observer and which is the source and which is moving or stationary is not the problem, the problem I am having is in solving the actual formulas... This question might belong in the math help section...

In the doppler effect equation for sound, measuring frequency, I have the following question: Car 1-20m/s--> Car 2-30m/s--> --POINT A-- With the above "diagram", we have car 1 going at 20 m/s, right, and car two, 30m/s right, with respect to point A (doesn't have to be those values...

I was reading somewhere that the because of the red shift it can be concluded that the galaxies are moving away from us. But still when we talk about stars, red color refers to cooler stars rather than stars moving away from us. Why?

do you get a doppler shift when your moving towards a light source? like, i know light gets redshifted with expanding space and gravity, but if light always approaches you at the same speed, how would frequency change there?

Doppler effect revisited Am I right when I say that the doppler effect formula "f=f0((v+vo)/(v+vs))" is derivated from the classical theorem of speed addition and this is why the doppler effect for light and EM waves is different?

If a source and detector are moving towards one another, for the general doppler equation, would this be considered the source moving or the detector moving?

I know that the typical values of Doppler coefficient over core life are about -1 *10^-5 Deltak/k/°F at BOL and -1.5 * 10^-5 Deltak/k/°F at EOL. What are the value in SI units? Are they the same, but in Kelvin? Thanks, Ken

when observing heavenly objects, there is an important role of doppler effect. but is there a way to distinguish whether the red/blue shift is because of translational, rotational motion or perhaps thermal motion of the atoms?

There is a space shuttle service between Earth and mars. Each spaceship is equipped with two identical lgihts one at the frotn and one at the rear. The spaceships travel at constnat speed u0 relative to Earth such that an observer standing on Earth sees the headlights of an approachin ship as...

For the relativistic doppler shift: change in wavelength = (c - Vs) To / (1 - Vs ^2 /c^2)^1/2 where Vs is emitter velocity, c is speed of light and To is time. Suppose change in wavelength was equal to just 1 / (1 - Vs ^2 / c^2)^1/2 then (c - Vs) To = 1 c -Vs = 1 / To c = Vs + 1...

Hi everyone, really would love it if someone could help me with this. I think it's probably a very easy problem, only I can't seem to find the right formlula, or understand the only one I found... This is the problem: I'm in my car, driving towards a crossing with a red traffic light...

Assuming the speed of light is constant from all reference points I don't quite understand why the Doppler Effect works for electromagnetic waves. From my understanding, as far as sound is concerned the object "catches up" with the sound wave, increasing the wave's frequency. But how can that...

A while back I was involved in a discussion regarding the difference between the classic Doppler Effect equation and the Relativistic Doppler Effect equation explaining red/blue shift in stars. I went looking for how to derrive both formulas and came across this interesting article that...

I saw in a chapter on special relativity a derivation of the transverse Doppler effect, which seemed okay, but I have a question concerning this: If the motion of a source is always perpendicular to the position vector connecting the observer to the moving source (i.e. the distance remains...

As I understand it, light will be redshifted when it travels from a large ( gravitationally speaking ) object to us. It will also be redshifted if the object is moving away from us. How do we know how much of the redshift is due to either effect ? :confused:

A train moving toward a detector at 31m/s blows a 305-Hz horn. What frequency is detected by a statiory train? Using the equation f´= f(V + Vd/ V - Vs) The answer is supposed to be 340-Hz but I don't understand how to get it. Mind helping me out?

What is "FOR"? doppler shift? What is "FOR"? I believe it an acronym having to do with the doppler shift? :confused:

Photon Doppler Shift? I am a practicing EE who has used the standard Doppler shift equation for thirty years in radar design; therefore, I am not disputing the correctness of the equation but the "explanation" that is so often given in textbooks. The general explanation always discusses...

The Doppler effect corresponds to a percieved change in the wavelength of impinging light, correct? Does this mean that the Absorption spectra we would see for bodies in relative motion to light sources should be the same independent of the type of motion between the body/source (assuming that...

relativistic doppler shift I'm trying to show that this equation for the doppler shift for light: f' = [&radic;(1+(v/c))/&radic;(1-(v/c))] * f reduces to &Delta;f/f = -v/c for v<<c So I expanded (1+v/c)^(1/2) = 1 + v/(2c) and (1-v/c)^(1/2) = 1 - v/(2c) dropping higher order terms on the...

My book derives two formulas for Doppler shift. One for when the source moves and one for when the observer moves. What about when both are moving? I tried deriving it myself... but I couldn't :( If you want, you could just give me a hint on how to derive it.

I've tried searching the forums, but to no real avail. Here's my question (it is not really related to the Doppler Effect formulas/equations, or derivations of them): Why is the observed frequency different when you have the source moving towards the observer at a given speed, and when you...

i'm reposting this here because for some reason my post moved to grade k-12 forum... btw this is a first year University physics question... this is from my physics assignment... after pulling half of my hair, i still couldn't figure it out... my answer for part a) is greater and lower...

this is from my physics assignment... after pulling half of my hair, i still couldn't figure it out... my answer for part a) is greater and lower and part b) is same and same... not sure tho... thx 4. Part a) A sister has a ball which she throws toward her brother. The ball is thrown...

i've been having a tough time trying to solve the following problem. A pulsating star has a period of 3 sec as seen from the rest mass frame of the star. What is the period of the star as measured by an observer traveling 2.2e8 m/s with respect to the star? I assumed that it was simply...

Consider a situation in which a light source is stationary with respect to an observer, A. This source emits n photons of frequency f, each of energy E = hf, towards A. Hence, A will be able to detect the energy loss in the source, which is E = nhf. Now, this light source is moving with...

Suppose we have a weightless light source that is moving. Its output light will therefore undergo a Doppler shift. Now, if the lightsource had weight but were static, its light would undergo a red shift. If the light source had weight and were moving, would it undergo both a red shift and a...

I’m on a train sitting next to an open window - it’s a bit stuffy - traveling towards a station. A siren is sounding at the station. As I travel toward the siren its pitch is higher that it would be if I were stood on the platform. Once I have passed the siren and I’m moving away, its pitch...

I am trying to understand how the doppler effect was used when determining that the other stars were moving away from us. I get that the spectral lines observed are shifted and by examining that data we can calculate how fast its moving and if it is towards or away from us. could anyone...

Using the doppler effect: formula: f'=f/(1-V_s/V_0) A train traveling toward you at 120k/h. the train blows its 400Hz whistle. take the speed of sound to be 340m/s. what's the freq? my developments so far... 400Hz/(1-(.340/.343ms) how do i solve the setup is wrong?

Hi All... Who knows the formula of the Dopler´s Effect??Please someone help me.This is a little curiosity that I Have.Regards. BlueIce88

I have a question regarding waves which has been bugging me for a while: "You are given a traveling wave with an equation of the form cos(ax+/-bt) where x and t are position and time as usual, a and b are positive numbers. Explain how you would physically determine the direction that the...