Doppler Definition and 749 Threads

Homework Statement A stuntwoman is preparing to take a punch, crash through a "candy glass" window, and fall a long distance. The script calls for her to emit a piercing scream just before she hits the "ground." In reality, she will land on a waiting airbag. Lights! Camera! Action! The...

If as a result of the equivalence principle we can derive the gravitational red shift entirely from the perspective of an accelerating body with no reference to gravity and no reference to gravitational time dilation then one is essentially just working out the Doppler shift of a signal...

I am a bit confused here. Is cosmological redshift the same as doppler redshift? This is from wikipedia: "The redshift z often is described as a redshift velocity, which is the recessional velocity that would produce the same redshift if it were caused by a linear Doppler effect (which...

A police car's siren emits a wave with a frequency of 60 Hz. The speed of sound is 300 m/s and the car is moving 50 m/s. "what is the wavelength of the wave behind the car" So, the answer seems pretty easy. The observer is a stationary point behind the car, and the source is moving away...

Homework Statement A siren emits a frequency of 900 Hz. Wind is blowing at a steady speed of 15.0 ms-1. The speed of sound in calm air is 343 ms-1. What is the frequency heard by someone approaching at 15.0 ms¹, (i) when the wind blows from the person to the siren, and (ii) when the wind...

Homework Statement Two jet airplanes are flying due east. The leading jet is flying at 1.3 times the speed of sound. The trailing jet is flying at 464 mph (both relative to the ground). The wind is blowing 182 mph due west. If the engine of the leading jet has a frequency of 2824 Hz, what...

Homework Statement a train moves with uniform velocity . its horn is with a definite frequency . then if the frequency that a man in the station had heard is changed from 5400 Hz to 4500 Hz . calculate :- 1- velocity of train. 2- the real frequency of the source . let the velocity of sound...

Doppler effect and Resonance--relationship? we have a structure called Menar Jonban (i.e. Shaking Minaret-- it's basically a minaret that could be shaken --- literally!..you shake one minaret and the other one shakes too!) ... obviously the best explanation of the phenomenon is resonance .. but...

In several threads where I've seen the redshift issue discussed there's been some confusion about this point, Must we treat cosmological redshift as a purely kinematic (relativistic)doppler effect or as the time dymamics of the metric space? Or both views can be made to converge?

Homework Statement -You are traveling in a car near a speeding train. The train whistle blows but you fail to hear the doppler effect. What conditions might prevent you from hearing it? Homework Equations The Attempt at a Solution -Ok, all I can come up with is that maybe...

Homework Statement The sound source of a ship's sonar system operates at a frequency of 23.0 kHz. The speed of sound in water is 1482 m/s. What is the difference in frequency between the directly radiated waves and the waves reflected from a whale traveling straight toward the ship at...

Hey all, I'm a newbie here with a question regarding doppler shift. Before I ask, I only have a very basic understanding of the doppler effect. So, my big question is: can a doppler shift measurement be converted to the distance between the source and target, without using the time of...

Hii guys.I have this problem.Can anybody help me on this.tq Homework Statement A satellite is in a circular polar orbit at a height of 870 km, the orbital period being approximately 102 min. The satellite orbit passes directly over a beacon at sea level. Assuming an average value of...

Doppler shift with microwaves...i think... Homework Statement Microwaves, which travel at the speed of light, are reflected from a distant airplane approaching the microwave source. It is found that when the reflected waves are beat against the waves radiating from the source, the beat...

Homework Statement A bus is moving at 37.00m/s towards a wall. The sound from the bus has an original wavelength of 0.1500m. The sound from the bus reflects off the wall. What frequency sound does an observer on the moving bus hear from the reflection?? Homework Equations Moving Observer: fo...

I need the following statements logically-'spellchecked'. The internet, nor books will put it this simply, so I typed up what I feel is a summary, but I don't want to be incorrect in my own mind by doing so. So please proof read my logic and correct it for errors: The doppler effect IS...

Homework Statement A plane mirror is moving at a uniform speed v away from the observer and a pulsing source of light of frequency f_0. What is the frequency of the light reflected in the mirror as seen by the observer? This isn't an actual homework question but I have a similar...

Homework Statement a. A fire engine is moving at 40 m/s and sounding its horns. A car in front of the fire engine is moving at 30 m/s, and a van in front of the car is stationary. Which observer hears the fire engine's horn at higher pitch, the driver of the car or the van? b. A bat flying...

Homework Statement A small homemade firework goes off 3 meters about the surface of the water where a person is diving. The diver is 10 meters below the surface of the water. (a). How much time passes from the instant the firework goes off until the diver sees it? (b). How much time...

Let's say i am in a car traveling at 0.5c relative to a truck- which is at rest relative to the ground- approaching me from the opposite direction. Relative to me, the truck is going at 0.5c. Both, truck and car, frames of references are inertial frames of reference. Therefore, the principle of...

Homework Statement *See attached diagram* On straight, level, parallel tracks separated by a distance d, two trains are testing their horns (in still air of density ρair). The horns (located at the train fronts) emit equal frequencies. Horn 1 is a pipe, open at one end, emitting a total power...

You are driving along a highway at 27.50 m/s when you hear the siren of an emergency vehicle traveling in the opposite direction on the other side of the highway. When the vehicle is approaching you, you hear the frequency of the siren as 2800 Hz, but when it is past you the frequency becomes...

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...

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...

A bat is approaching a wall. If it is traveling at 10 m/s and squeaks at 80 kHz, what frequency does it hear in its echo? f=fo(1 +/- vo/v) f=fo (1/(1 +/- vs/v)) So I got the right answer by initially making the wall the stationary "observer" and the bat the moving source, and finding...

A bat is approaching a wall. If it is traveling at 10 m/s and squeaks at 80 kHz, what frequency does it hear in its echo? f=fo(1 +/- vo/v) f=fo (1/(1 +/- vs/v)) So I got the right answer by initially making the wall the stationary "observer" and the bat the moving source, and finding...

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...