I have an obvious understanding failure here, so hopefully someone can help me clear this up. Thanks for reading this obnoxious drivel.Leading clocks lag
So, if two clocks are fixed to a the ends of a barn, and they are set off with light pulses from the midpoint, in the frame of the barn the...
I have seen few examples on Doppler effect and i am confused about one such.
We are standing on ground.
If the source of sound S moves and Object O is stationary. We would presume the frequency as well as wavelength of sound be changed to the obeject O.
But if O moves towards or away from S...
RV Jones gave the 1981 Christmas Lectures "From Magna Carta to Microchip" which explores what measurement is, the principles by which measurements can be made, and why their applications have been of so much importance in the advance of science and in the development of technology.
Hello all, (1st post)
I would like some help with deciding if the source is moving towards the observer or vice versa in Doppler effect situations.
The example that I am confused about is a skydiver holding a constant frequency emitting source during the descent. The skydiver is traveling at...
Homework Statement
Two trains A and B have a whistle that blows at a frequency fT = 392 Hz. Train A is stationary and train B is moving toward the right (away from A) at a speed of vB = 35 m/s. A listener is between the two trains and is moving toward the right with a speed of vL = 15 m/s. No...
Homework Statement
Homework Equations
frequency of observer = frequency of source[(V +- Vo ) / (V-+Vs)]
The Attempt at a Solution
I am not completely understanding this question. I kinda understand that the frequency of the siren does not depend on the distance between the motorcycle and...
Homework Statement
Homework EquationsThe Attempt at a Solution
When the source is not moving, ## \lambda = 6250 A ## ...(1)
When the source is moving, ## \lambda ' = 6500 A ## ...(2)
From (1) and (2),
## \lambda ' > \lambda ## ...(3)
This means that the source is moving away from...
Homework Statement
A microphone is suspended from a spring attached to the ceiling. Directly below, on the floor, is a source of sound that is emitting at f=440 Hz. The microphone vibrates vertically in simple harmonic motion (SHM) with a period of 2.0 seconds. The difference between the...
Hi,
Can someone please anlayse the visual effects for light travel in the documentary 'Journey to edge of the universe'
Especially around the 43:12 and the 1:02:20 mark.
Can you also tell me if it is or is not an accurate depiction of what we should be seeing theoretically?
Homework Statement
A body emits photons of frequency ##\omega_*## at equal rates in all direction in its rest frame. An observer is moving with speed V relative to the body in the x direction. Find the rate at which the photons are received per unit solid angle ##dN/dt'd\Omega'## a large...
Just a quick question I got in my mind while reading up about fission, the so called Doppler effect which manifests itself in fertile material like U238, I read it helps control reactor stability , hence the majority of fuel consists of U238, as the fuel heats up at some point, U238 starts to...
Homework Statement
To determine the speed of a train, a student of Physics determined the frequency of the whistle in the approach to its position of observation, and measured 220 Hz. He then determined the frequency of the whistle when the train moved away, and got 190 Hz. What is the speed of...
I was driving the other day, and I was about to go past a green light when it turned yellow, so I sped up. I got past the light but but it got me wondering, how fast would you need to go for a red light to appear green due to the Doppler Effect.
(Excuse me if this question doesn't belong in...
Homework Statement
2. Homework Equations
Doppler's Equation
The Attempt at a Solution
(1)[/B] freqA = (v sound - vA )/(v sound - v B) . freq B
*v A = 0 (static)
= V/(V - v) . freq B ...Answer : (d)
(2) freq A hear which is reflected sound by D
first find freq D, *v D, v A = 0...
I would like to know the formula for calculating the Doppler shifted frequency received by someone on Earth that is received from a spaceship traveling at 85 percent the speed of light away from Earth. Please show example of the formula being used. Let's say the spacecraft sent a radio signal...
Hi,
I was looking into Doppler shift calculations, and I came across this blog post. It gives a very simple and straight forward account of calculating the velocity of a star.
Following is the summary the blog post:
Spectrum of Alpha Centauri (A. Cen.) is obtained through Lhires III...
Hello! I am a bit confused by the Doppler effect. Based on the formula it seems that if the source moves towards me with speed ##v## I hear a frequency ##\nu_1## but if I move towards the source with the same speed ##v## I hear a different frequency ##\nu_2##. However according to the...
Homework Statement
A stationary police car emits a sound of frequency 1200 Hz that bounces off a car on the highway and returns with a frequency of 1250 Hz. The police car is right next to the highway, so the moving car is traveling directly toward or away from it. (a) How fast was the moving...
Consider at stationnary radar at the origin ##z=0## and a target (speed ##v##) moving along the ##z## axis and away from the radar. The radar is sending plane waves (frequency ##f_i##) to the target and they come back to the radar (the radar is then both an emitter and a receiver). I am...
So I have a strange question. I study snakes, which are of course sensitive to vibrations in the ground. A common technique for finding snakes is to drive roads at night. A constant debate that comes up among herpetologists is whether or not the vibrations of the vehicle are causing the snakes...
I have learned that the Doppler effect causes a change in wavelength (and thus frequency) in all types of waves
Suppose there is a radio station transmitting waves of frequency 90 kHz and the antennae in my car is tuned to that frequency.
Then I start to accelerate and thus I am changing my...
Homework Statement
An avant-garde composer wants to use the Doppler effect in his new opera. As the soprano sings, he wants a large bat to fly toward her from the back of the stage. The bat will be outfitted with a microphone to pick up the singer's voice and a loudspeaker to rebroadcast the...
Homework Statement
A train moves at a constant speed of v = 25.0 m/s toward the intersection shown in Figure P13.71b. A car is stopped near the crossing, 30.0 m from the tracks. The train’s horn emits a frequency of 500 Hz when the train is 40.0 m from the intersection. (a) What is the...
Homework Statement
A source emits sound with a frequency of 860 Hz. It is moving at 20.0 m/s toward a stationary reflecting wall. If the speed of sound is 343 m/s, what frequency does an observer riding with the source hear?
A
860 Hz
B
913 Hz
C
910 Hz
D
765 Hz...
Light consists of quanta(small packets of energy). Then how do we explain doppler effect of light the same way we do for sound? What is the valid explanation of light doppler effect which is consistent with the photon picture?
Homework Statement
An audio transmitter and receiver are mounted side by side as shown in the figure. The transmitter emits sound of frequency v. A distant flat plate approaches the instrument at speed Vtarget and the receiver detects sound waves of frequency v' reflected from the target. The...
In his seminal paper on Special Relativity: On the Electrodynamics of Moving Bodies, Einstein derives a formula for the Relativistic Doppler effect.
See this section:
§ 7. Theory of Doppler's Principle and of AberrationThe formula is: In this Wiki article, the same formula is derived.
The...
Hello, I have an exercise here that I need help with.
The precision in measurements of radial velocities by the Doppler effect is currently 1 m/s. Can a Jupiter like planet orbiting a star similar to the Sun at a distance from the mother star equal to the Sun-Jupiter distance be detected? (Use...
Temperature is the average of the kinetic energy of the particles, if the bunch of particle moves fast and you look at the particles in two differece frame of reference, on steady with the bunch of particles and the other not, in the last one you get an higher temperature of the bunch of...
Homework Statement
I'm watching this lecture and wanted to attempt to derive the expression for ΔTo/ΔTs
Homework Equations
ΔTo = ΔTs + VΔTo / U
The Attempt at a Solution
I have worked out that ΔTs = 1-V / U, however I'm stuck trying to get ΔTs / ΔTo because of the ΔTo on both sides of the...
[Note from mentor: this thread was originally posted in a non-homework forum, therefore it does not use the homework template.]
I have been given an equation for the relativistic doppler effect but I'm struggling to see this as a function and then give a first order Taylor expansion. Any help...
Homework Statement
http://www.physics.ox.ac.uk/olympiad/Downloads/PastPapers/BPhO_Paper3_2004_QP.pdf
question 3. Should i post a picture of it if its more appropriate ?
Note: I'm expected to do this in about an hour
[Mentor note: Image of the relevant portion of Q3 inserted]
Homework...
Let's say you have a sound emitter and receiver a fixed distance apart on a moving object but open to the air, such as on the hood of a car. The emitter is near where the windshield wipers are, and the receiver is closer to the grill. They are in aligned along middle of the car, longitudinally...
What happens if a source and the observer move at the same direction?
Always hear how only one of them doesnot move, or when they move towards each other.
For example. An ambulance moves towards direction A with Va. A biker moves towards direction A as well, with Vb.
What happens to the...
I think the relativity provides the Doppler shift (in a radar - double version) in a form:
##\frac{1-v}{1+v}##
which is quite simple, as a square of a single Doppler: ##f' = f\sqrt{\frac{1-v}{1+v}}##
But I never seen what is a classical version of this - what is a formula for a radar shift in...
I would like to be sure about one case of the use of Doppler effect with sound waves.
If the medium (in the case of sound air) is moving, but there is no relative motion between the observer and the source there is no Doppler effect at all. (And the absence of relative motion is...
Hi All,
What is the explanation for the fact that doppler effect has an asymmetry with relation to the relative movement fo the source and the observer? For instance,
## \frac{v + 5}{v} \neq \frac{v}{v -5}##
The version I have seems to be somewhat truncated to me; it simply relates this fact...
Homework Statement
A source emits a spherical sound wave at frequency ##f=110Hz## with power ##P=1 W## in a solid angle of ##2 \pi sr##. An observer moves with velocity ##v_{oss}=108 km/h## towards the source. Determine the sound intensity level received by the moving observer.
Homework...
When thinking of sound waves (or more commonly seen waves) the doppler effect is fairly obvious.
A car is moving away from you, it's horn's membrane is fluctuating, increasing & reducing air pressure over time. So if it's moving away from you the sound's peak would occur further away...
Homework Statement
Consider two parallel walls perfectly reflective placed at the distance ##d = 0.8 m ##. A ball, provided with a device through which are emitted continuously frequency sound waves equal to ##f_0=430 Hz##, is launched from one wall to another. It moves with constant velocity...
Hello,
It kind of bothers me that the derivation for the Lorentz transformation relies on two dimensions of space. (Here I am referring to the standard derivation where one person is using a vertical light clock in a trolley traveling horizontally at speed v, and an observer outside is...
Homework Statement
A driver of a car traveling towards a wall with a speed of 5m/s, sounds a horn of frequency 256 Hz. If speed of sound= 330m/s, find
a) No. of beats /sec if the observer is between the car and the wall.
b) No. of beats/sec if the car is between the wall the observer.
c)...
Galaxies that are greater than a distance of c/H metres from Earth have recessional velocities exceeding the speed of light and begin to fade. Thus, theoretical astronomers 3 trillion years in the future will see only the Milky Way in the night sky. What is the reason for this fading of galaxies?
Say we have an observer in perfectly circular motion around a source, like a star.
Is it reasonable to apply the angle change formula ##cos \theta_o = \frac{cos \theta_s - \frac{v}{c}}{1-\frac{v}{c}cos \theta_s}## and then take the component of the motion parallel to the light wave in the...
Homework Statement
I have this Doppler effect formula, but I don't know how it was derived, I can't repeat the process myself to solve for speed of the source, I would really appreciate if someone could mathematicly solve this in steps, thank you very much.
Homework Equations...
I have been trying to find an per reviewed article where it is actually tested that sound does not have a transverse Doppler effect. I figure that its probably do to my lack of resources. if it is could somebody give me a link to the article i would appreciate it. If not, i must ask why has it...
Homework Statement
A motor scooter moving at 10 m/s approaches and passes a police car moving at 50 m/s in the opposite direction. The frequency of the siren on the police car is 700 hz when the car stands still. the difference in frequency heard by the driver of the scooter between when the...
Homework Statement
A guitar player is plucking a strong of length 30cm. How fast must the player move towards or away from the stationary observer, in order for the observer to mistake the fundamental frequency for the second harmonic?
ANSWER: 2(Vsound) towards the observer
Homework...
Homework Statement
When a train running at a speed of 72 km/h approaches a crossing signal, a passenger in the train hears the siren at 720 Hz. What frequency does the passenger detect after the train passes the crossing signal? Take the speed of sound in air to be 340 m/s.
Homework Equations...