Doppler Definition and 713 Threads

Homework Statement A laser of frequency f0 is connected to a spring which oscillates in one dimension with a period T and amplitude A. The laser excites the 1st four Paschen series lines of hydrogen. What is f0 Homework Equations I'm assuming that I'll need the Doppler shift equations, f =...

Homework Statement A speaker is attached to a wire 1.5 m long and is spun in a circle at 2 rev/s. The speaker is connected to an electric piano on which a child is playing a note at 261 Hz. Speed of sound in air is 343 m/s. What range of frequencies will the stationary observer hear? I...

[SIZE="4"]Could anyone who knows give me a really simple yet realistic explanation of the doppler effect. This is one of those things that just boggles the brain so to speak.

Homework Statement A jet is flying horizontally from A to B. When the plane is directly overhead at B, a person on the ground (C) hears the sound coming from A. ABC is a right triangle in B. The angle BCA = 36 degrees. The average temperature is 20 degrees Celsius. If the speed of the plane...

Homework Statement John is listening to a horn. He knows the frequency of the horn is 300 Hz when both he and the horn are at rest. If he hears a pitch of 270 Hz, there are clearly several possibilities. For each of the following statements, indicate whether it is correct or incorrect...

I'm having a hard time understanding some things regarding the doppler effect. Please excuse my Microsoft paint diagram, I'm no artist. http://img686.imageshack.us/img686/3949/diagram.jpg http://img686.imageshack.us/img686/3949/diagram.jpg" Given this scenario, which...

Homework Statement An observer is in rest.A source of sound is in rest.A wind blows along the line joining the observer and the source.What all remain same in these: a.frequency b.velocity of sound c.wavelength Homework Equations f prime=f(v+w-vo)/(v+w-vs) Doppler effect The...

Homework Statement A car speeds towards the outside wall with its horn sounding a frequency of 160 HZ. The sound waves reflected off the wall cause the driver to hear 8.0 beats per second. There is no wind and the speed of sound is 343 m/s. Find the speed of the car. Homework Equations...

i am now studying the Doppler effect in a thermal atomic gas If an atom travels in velocity v along x direction at some time, it emits a photon in some direction the momentum of the emitted photon can be well approximated with the free one thus the momentum of the atom after the...

i am now studying the Doppler effect in a thermal atomic gas If an atom travels in velocity v along x direction at some time, it emits a photon in some direction the momentum of the emitted photon can be well approximated with the free one thus the momentum of the atom after the...

Homework Statement Hearing the siren of an approaching fire truck, you pull over to the side of the road and stop. As the truck approaches, you hear a tone of 460 Hz; as the truck recedes, you hear a tone of 420 Hz. How much time will it take for the truck to get from your position to the fire...

Homework Statement A commuter train passes a passenger platform at a constant speed of 40 m/s. The train horn is sounded at its characteristic frequency of 320 hz. A) What change in frequency is detected by a person on the platform as the train passes? B) What wavelength is detected by a...

Can someone give me an idea on our Investigatory project about Doppler Effect...? Our project shouldn't be amounting in an expensive one. I am only 4th year high school student and so confuse what project will i make... Please Help me guys. Thanks in Advance Guys!

sorry lots of reading but i wanted to explain what I've done (tried to do) Homework Statement An ambulance has a loud siren, which emits a pure note at 5100Hz. A man 20 m from a straight road along which the ambulance is travelling, and records the frequency of the sound he hears from the...

Easy/fustrating doppler question - rather urgent Homework Statement A swimming duck paddles the water with its feet once per time interval of 1.4 , producing surface waves with this period. The duck is moving at constant speed in a pond where the speed of surface waves is 0.31 , and the...

Homework Statement Sally is a police officer who is standing in an intersection. A car driven by David approaches the intersection at a speed of 75 km/h. Sally blows her whistle (at a frequency of 900 hz) and signals the driver to stop. What does frequency does David hear? (speed of sound is...

Homework Statement A car is approaching a reflecting wall. A stationary observer behind the car hears a sound of frequency 745 Hz from the car horn and a sound of frequency 863 Hz from the wall. 1. How fast is the car traveling? A. 25.2 m/s B. 33.4 m/s C. 18.9 m/s D. 54.2 m/s 2...

1. The problem statement 1) A train whistle has a frequency of 1000 Hz. If the train is speeding at a velocity of 60 km/h past a stationary railroad crossing attendant, what is the apparent frequency a) as the train approaches him, b) as it moves away from him? Assume speed of sound to be...

Homework Statement A train approaches an observer at 35.0 m/s and passes a person stading on the side of the track. The whistile is sounding at 2.5 kHz. What frequency will the person hear as the train approaches? When it recedes? Homework Equations f' = f \frac{v \pm vo}{v \mp vs} The...

I am new at this so I hope you all will excuse me if I am stupid. But I got this idea about the graviton. If it is a wave then it should display some sort of doppler shift when it moves with respect to the observer. So there it is , somebody tell me why I am dumb.

You can know the temperature of a star by fitting a black body spectrum. BUt what if the star is moving with some radial velocity v? I worked out that: I(\lambda_0,T)=\frac{8\pi h c}{\lambda_0^5}\frac{1}{e^{\frac{hc}{\lambda_0kT}}-1}...

Homework Statement For a mobile receiver operating at a frequency of 900MHz and moving at 100Km/hr. Homework Equations Find Doppler frequency. The Attempt at a Solution

lol :-p http://improbable.com/2009/11/13/doppler-effect-with-a-dogs-squeak-toy/

There's something I don't understand about the Mossbauer effect. I understand that the Mossbauer effect has a mechanism for eliminating the energy shift due to the recoil of the nucleus, since the inertia can be the inertia of the lattice over-all, rather than the inertia of the individual...

Homework Statement What sort of frequency shift does a rocket ship traveling along the x-axis as some speed close to c observe when it passes directly over a light source emitting photon on the y-axis (so when the angle between them is 90 degrees). At this angle, the rocket is neither...

A very basic question (I hope this is the right place for it). A distant star emits, say, a high-energy x-ray. Due to expansion of space, this reaches us as visible light (say, red part of the spectrum). The light that reaches us has less energy per photon (E=h*nu) then the light emitted...

Homework Statement The Enterorise NCC1701 is cruising 0.6c above the moon of Eridani when it spots a Klingon warbird sunwards. i. It fires a proton torpedo at speed 0.75c relative to the ship at the Klingon warbird. Assuming the proton torpedo does not accelerate, at what velocity must the...

Homework Statement An astronaut is said to have tried to get out of a traffic violation for running a red light (lambda= 670nm) by telling the judge that the light appeared green (lambda= 540nm) to her as she passed by in her high powered transport. If this is true, how fast was the astronaut...

Homework Statement The hydra cluster is 900 Mpc (3x10^9 light years) away. Calcium atoms emit a spectral line of wavelength 396.8 nm. This line is observed at 487.5 nm. The velocity of the cluster, v, is given by (\lambda =c/f) 487.5 = 396.8 SQRT((1+v/c)/(1-v/c)) How do i find v please...

Homework Statement Three radio-equipped plumbing vans are broadcasting on the same frequency f_0. Van 1 is moving north of van2 with a speed of v, van 2 is fixed, and van 3 is moving west of van 2 with a speed of v. What change in frequency (f-f_0) does van 3 hear from van 1? Homework...

Homework Statement You are in charge of calibrating the radar guns for a local police department. One such device emits microwaves at a frequency of 2.15 GHz. During the trials, these waves are reflected from a car moving directly away from the stationary emitter. You detect a frequency...

we know...when a source is running towards the listener...the wavelenth of sound become small and number of waves inceases...as far as i know ..the logic behind is..when a source runs..then waves become congested in a small distance between source and listener...it is so far so ridiculous to me...

I've heard it said that it is impossible to determine an objects absolute velocity, all one can do is find it relative to some other object... but, if the CMB is everywhere, why could you not just measure the doppler shift in all directions, and adjust your velocity so the CMB has no doppler...

Homework Statement Derive the doppler shift equation from the equation in terms of frequency to one in terms of wavelenght. Clues: frequency=c/lamda, use Taylor's expansion, velocity of source is much smaller than velocity of wave. c-velocity of wave v-velocity of source f-frequency...

One paper claims that the flyby anomaly only exists because NASA scientists forgot about the transverse Doppler effect. If that's true, why is it still called an anomaly? Why isn't everyone banging their heads on walls and thinking, "D'oh! I can't believe I forgot about that!"? If it's not...

When an ambulance approaches, its siren sounds shriller than when I relatively motionless to it, and vice versa. Such is an example of doppler effect, isn't it? However, there one thing I am not sure: does the siren gradually becomes more shriller when the ambulance approaches, or not...

doppler effect quick question! Homework Statement An ambulance traveling at speed 31 m/s is producing a loud sound of frequency 895 Hz. You see the ambulance in your rear view mirror as the ambulance approaches you and you slow down to 14 m/s as a law obeying citizen (hehehe we know now)...

Homework Statement An ambulance is running on an expressway at a speed of 60 km/h from east to west (from A to B) with a siren of 880 Hz. Let the frequency of the siren sound detected by an observer located at a point O be Va and Vb when the vehicle just passes point A and point B respectively...

If the energy of an EM wave = h x f and when a light emitting body (of a particular power) is moving toward or away from the observer the observed frequency changes, does the energy change? If so where does the gained or lost energy come from?

I have a problem in regard to the doppler effect,which may be generalised to all waves--sound,water etc. Please explain why the observed frequency increases as the object approaches an observer and then decreases as the object passes the observer.Actually,I thought that since doppler effect...

Alice and Bob are each in their own spaceship, and are traveling radially, initially away from each other, and subsequently toward each other, at some highly relativistic relative speed, say 99c. Each ship emits light flashes toward the other. Alice observes the light from Bob's outbound...

Hi, I've got a problem that I can't seem to find an explanation to, about the Doppler Effect An ambulance is going down the road at a speed U meters/second, in the same direction as the wind, which has a speed of W meters/second. The speed of sound in air is c meters/second Now, I have to...

Homework Statement A loud speaker is connected to a string (spring constant k = N/m). The speaker moves back and forward in simple harmonic motion with an Amplitude of 0.8m. The frequency of an oscillation for amass on a string is w = (k/m)^1/2. The mass of the speaker is 90.0g. What is...

Homework Statement A bat flies toward a wall, emitting a steady sound with a frequency of 25.0 kHz. This bat hears its own sound plus the sound reflected by the wall. How fast should the bat fly, v_b, to hear a beat frequency of 220 Hz? Take the speed of sound to be 344 m/s...

Hi, I'm new to these forums. I just had a question about the Doppler effect on light (red and blue shifts of light). I've read how it is supposed to work, but I also read in a book that the speed of light is constant in all moving frames. So if you've got a galaxy moving towards you, and...

Doppler Effect- Observer On Angle To Source Plz help- I've been working on this for 2 days and I'm down to my last teaspoon of coffee powder. Even having the answer didn't help! I think sleepness is turning me into a zombie :eek: ...prehaps eating brains will help me solve this problem...

I am trying to grasp how Maxwell's equations and energy/photons are related in a doppler shift problem. The way I stated it seems to have attracted non-serious hecklers; so I am trying to restate the problem for people who know Maxwell's equations and are familiar with engineering. In...

Hello All, I have been challenged by a friend to look into Gravitational waves and some questions he has about them -- but I have always been a slow starter. Took physics with SR in college, got my BSEE, happily can build analog circuitry of all kinds -- but found that certain questions about...

Homework Statement Standing in line next to the scariest rollercoaster of all time, you see your friends screaming their heads off as they come speeding out of the end of the ride. The sound of their screams is about 30% higher in pitch than normal due to the Doppler shift caused by their...

Homework Statement source emits sound with a characteristic frequency of 640 Hz. Calculate the observed frequency and the wavelength between source and observer in each of the following situations. a) The observer approaches a stationary source at 57 m/s b) Both the source and observer move...