Doppler Definition and 713 Threads

Could "Redshift" not result from the Doppler effect? Redshift is the astronomical phenomenon where galaxies and other far-away objects appear shifted to the "red" side of the visible light spectrum. The farther an object is from us, the more pronounced this shift is. This phenomenon is most...

A police car is traveling at a constant speed of 100. km/h with a radar gun which generates and detects radiowaves. The police car and the ambulance drive directly towards each other. The radar gun produces radiowaves with a wavelength of 0.0650 m. What doppler shift (Δf = f′–f) is detected...

Hello, This one has been bugging me for a while. When you drive a car past parked cars that are somewhat close, with the window down, there is a rhythmic whooshing sound. This sounds very much like numerous dopplershifts, but I have difficulty seeing it as a doppler shift because the parked...

Homework Statement A car and a bicycle are traveling directly toward each other at different speeds. The car horn has a frequency of 440Hz, and the car is traveling at 15.0m/s. The cyclist hears a sound of frequency 467Hz. The velocity of sound in air is 343m/s. i) Calculate the frequency of...

I recently heard about the effects from The Doppler Effects at high relative speeds (significant fractions of c). For example you will eventually will even get burned/die by the radiation of the CMBR being ao intensly blueshifted while you're approaching the speed of light (relative). So...

Could someone explain how the relativity of simultaneity and the doppler effect are different?

I know its to do with the drop of frequency when the object that is making the noise passes you, but what exactly is it? I don't know much about it.

If the doppler effect is the changing if wavelengths due to movement of a light source (In reference to light of course), does this mean the distance between the wavefront and the source changes at a speed DIFFERENT from C? doesn't this mean that if the observer is in the plane of the source the...

Hi all. I am asking for some help with getting a physical intuition for the following situation: Consider an observer and source, at rest. The source emits sound waves of a particular frequency, 'f'. Letting the medium (air for example) between the source and the observer move with a particular...

hello,everybody .Doppler coefficient will be positive?

Homework Statement In the figure, a motionless observer stands between sound sources A and B, which oscillate at 338 Hz and 342 Hz, respectively. The observer hears a beat. Next, when the observer begins moving at a constant speed on the straight line connecting A and B, the beat is no longer...

How are measurements done in the Doppler Orbitography Radiopositioning integrated by satellite.Please tell in detail.Or books related to it.

Given the Doppler shift equation quoted here: http://en.wikipedia.org/wiki/Doppler_effect#General \frac{f_r}{f_s} = \left(\frac{c + v_r}{c + v_s} \right) where c is the velocity of waves in the medium; vr is the velocity of the receiver relative to the medium; positive if the receiver is...

I tried to wiki this,which stated relativistic doppler effect takes time dilution into account,but the analogy/example given was not related to time dilution..can anyone summarise both with a practical situation or a useful link for it Thanks in advance

Homework Statement I'm working on this problem here: http://hyperphysics.phy-astr.gsu.edu/hbase/astro/redshf2.html The answer is already listed, it's the steps I'm worried about. I don't see how they get from step 1 to step 2 here. They don't even tell me what T is. It seems...

doppler formula help please!:) Hello, i see the doppler formula in 2 different forms one being f1=f2 (Vw/Vw-Vs) and the other f1=f2/(1+Vs/Vw) f1= Doppler frequency f2= Source frequency Vw= Speed of sound Vs= Speed of source the problem i am having is understanding how these are...

I was considering the following question; 'A fire engine traveling at 70m/s drives past a van traveling at 30m/s. The speed of sound in air is 330m/s and the fire engine has a frequency of 200Hz when stationary. At what frequency does the van driver hear the siren?' I understand you have...

If this is the wrong place to be posting this, feel free to lock this thread. I wasn't sure if this belonged in "classical physics" or "quantum physics"; this seemed like the appropriate place, but I'm not 100% certain, as it does involve subatomic particles. Anyways, to get to the matter at...

Homework Statement Radar is used to measure the speed of passing vehicles. A stationary radar gun emits EM radiation, a proportion of which is reflected from the target vehicle which is moving away from the gun at 'u' ms^-1. a)State the frequency at the target vehicle (f.tar) in terms of...

Consider a stationary observer and an emitter of light radiation that may be either receding or approaching at a variety of nonrelativistic velocities, with the velocity of the emitter having only a radial component and no transverse component. I was wondering whether the Doppler Effect...

Ive been going through some landers of Venus and Mars and I found they were equipped with radio doppler experiment(http://en.wikipedia.org/wiki/Venera_9 ) I was wondering what this does. I mean there is radio signal transmitted through space everywhere and i suppose the device would measure...

I love to do mathematics, but apply it to usually classical physics, and no doubt quantum mechanics (since it's mainly just maths), and most other things except some astronomy. I don't mind calculating the orbits and so on, but I don't like calculating doppler shifts and etc. Does anyone else...

A source and a receiver is at rest with each other. Source emits some couple of light pulses, and stops emitting more. 1. The pulses is not reached to the receiver yet, and source starts moving. Does the receiver experience doppler effect with the emitted pulses? 2. The pulses is not...

Assume a object in motion emits a beam of light at an observer. The observer detects a frequency that is higher than the original frequency. That is the measured energy of the photon by this observer is higher than it was while emitting. How to account for this extra energy? thanks, kalpak

Homework Statement How to find the radar resolution? Homework Equations Doppler frequency = 2v/wavelength f = 2B R = ct/2 The Attempt at a Solution I don't know how to take the length of the aircraft into consideration. I only know how to calculate the doppler frequency but not the range...

In my physics books it gives an equation of frequency for a moving observer as f'= v'/λ =v+u/λ. Since λ=v/f it was converted to f'=v+u/(v/f) = (v+u/v)f I understand this much of the equation, but the final Algebraic factoring that I don't get is they said this equation is f'=...

Homework Statement You are cruising to Jupiter at the posted speed limit of 0.1c when suddenly a daredevil passes you, going in the same direction, at 0.3c. At what wavelength does your rocket cruiser's light detecter "see" his red tail lights? Is this wavelength ultraviolet, visible, or...

To find out how fast you would have to be going in order to to see a green light when the light is infact red what doppler equation would you use. I used f = ((c+v)/c)*f0. Is this wrong, if so why?

From the special relativity theory , for explaining the red-shifting of a photon, that has been red-shifted, is the following: point O: origin point of emitted photo, in Galaxy GlxO point R: receiving point of photon, in Galaxy GlxR GlxO, O ---------->----------------R, GlxR Suppose...

I have re-written this as as I accidently deleted my original post. I was wondering if the relativistic Doppler shift of a reflection from a mirror moving away from the observer was the same as the Newtonian equation in the special case that the mirror is orthogonal to the direction of motion...

Homework Statement A detector initially moves at a constant velocity directly toward a stationary sound source and then (after passing it) directly from it. The emitted frequency is f. During the approach the detected frequency is f'app and during the recession it is f'rec. If the...

Homework Statement The observer sees first spaceship that is moving from the right towards him with the speed v_r=0.6c, and the second ship that is coming from the left with the speed v_l=0.8c. If the first ship emits a signal with the frequency of 10^4 Hz (measured in the reference frame...

Homework Statement There is a question asking the frequency of a distant location from two rotating speakers which are attached to the both ends of a meter ruler. The ruler is rotating ar 7 rounds per second and A speaker has a frequency of 500Hz. At the given time they are in a position which...

does doppler effect affect ENERGY of photon?? i have tried to make the question as clear as possible,but in the process,have made it a bit too long. i request you to be patient- suppose a source is emitting a photon after equal intervals of time.an observer,who was initially at rest w.r.t the...

When I ask for differences I am not meaning mathematical ones since that it is obvious: We have a phenomenon p, p can be described by Galilean Relativity (GR) and by Einsten Relativity (ER). ER(p)!=GR(p) The math expression that describes this phenomenon is different. Then the doppler...

Homework Statement A woman is riding a bicycle at 18.0 m/s along a straight road that runs parallel to and right next to some railroad tracks. She hears the whistle of a train that is behind. The frequency emitted by the train is 840 Hz, but the frequency the woman hears is 778 Hz. Take the...

Homework Statement A policeman detects a drop of 10% in the pitch of the horn of a motor car as it crosses him. If the velocity of sound is 330ms^-1, calculate the speed of the car. Homework Equations f2 = f1 [v - v(listener)]/[v - v(source)] where f2 = apparent frequency f1 =...

The image shows four points. "A" is source of light and "B" is receiver, and "a" and "b" represents co-ordinate points. "A" is moving with constant speed to "B". "B" feels doppler effect. If "B" moving with constant speed to "A", then also "B" feels doppler effect. Statement 1: This two...

Homework Statement A microphone is attached to a spring that is suspended from the ceiling. Directly below on the floor is a stationary 540-Hz source of sound. The microphone vibrates up and down in simple harmonic motion with a period of 2.20 s. The difference between the maximum and minimum...

Homework Statement Two auto-mobiles are driving on the same road in opposite directions. The speed of the first auto-mobile is 90.0 km/h and that of the second is 60 km/h. The horns of both auto-mobiles emit tons of frequency 524 Hz. Calculate the frequency that the driver of each...

Lets say we have some particle A 1m above the ground. Let it has velocity v. Also let's consider gravitons like the reason/mechanism of the gravitation. Let gravitons moves away from the Earth with velocity c. Now let's consider the differences between two cases: 1 when particle A moves down...

When a source emitting a sound of a specific frequency moves towards the face of a cliff at a speed. The frequency of the sound that reaches the cliff is for sure not the same as the frequency emitted from the source due to doppler effect. Will the frequency of the sound reflected by the cliff...

Homework Statement P15. The police car with its 300 Hz siren is moving toward a warehouse at 30 m/s, intending to crash through the door. What frequency does the driver of the police car hear reflected from the warehouse? (5 marks) Homework Equations doppler shift for an approaching...

Homework Statement How fast would a star have to travel to make violet light (λ = 400 nm) appear to be blue (λ = 450 nm)? Assume the star is moving along the line that connects the star to the Earth. Homework Equations λr = λc / (c-Vr) f= fo (c +- Vr / c +- Vs) The Attempt at a...

Homework Statement Estimate the Doppler shift for a radio wave reflected from an airplane moving directly toward you at a speed of 292 m/s. Assume the radio wave has a frequency of 9.7x10^6 Hz. Homework Equations fo = fv/(v − vt) The Attempt at a Solution Using the above...

So I'm having a hard time getting the second part of the problem, so could anyone help me An ambulance travels down a highway at a speed of 65.0 mi/h, its siren emitting sound at a frequency of 4.10 102 Hz. Take the speed of sound in air to be v = 345 m/s. What frequency is heard by a...

The Doppler Effect -- frequency of a bat reflected on wall Homework Statement A bat flies toward a wall, emitting a steady sound with a frequency of 22.0 kHz. This bat hears its own sound plus the sound reflected by the wall. How fast should the bat fly to hear a beat frequency of 190...

Homework Statement A sound source emits sounds of frequency 210 Hz that travel through still air at 340 m/s. The listener moves at 85 m/s relative to still air toward the stationary source. What is the wavelength of the sound between the source and the listener? Homework Equations f' = f[1+...

Hello everyone! I need some help with a Doppler effect/relative motion question. Homework Statement A whistle with a frequency of 1200 Hz is traveling south at a velocity of 30.0 m/s. You are traveling north away from the whistle at a speed if 18.0 m/s. If the speed of sound is 340 m/s, what...

Hi! I have two (stupid) questions: 1) We can determine what elements are present in distant stars by studying their spectrum, right? But if the spectrum of some star is redshifted, wouldn't we be fooled into believing some elements to be present there that might not really be there, due to...