Propagation Definition and 487 Threads

Homework Statement Given the following EM wave propagating in vacuum, find the direction along which the electric field oscillates and the direction of propagation of the wave: \vec{E} = (-3\hat{i} + 3\sqrt{3}\hat{j}) 10^4 e^{i[\frac{\pi}{3} (\sqrt{5}x + \sqrt{5/3} y10^7 - 8.1246 *10^{15} t]}...

Completely new to the concept of errors and don't know how to approach this... Calculate value and error in Z Z= 2AB^2/C Where A= 100 Error in A= +/- 0.1 B= 0.1 Error in B= +/- 0.005 C= 50 Error in C= +/- 2 Plugging in the numbers Z= 0.04 How do you carry the errors...

1-In a bottle of water,transverse waves propagte on the surface of water,while lognitudinal waves propagate in depth..what explains this? What makes different kinds of waves propagate through water not the same kind? You may tell me that is not true because surface waves propagates on the...

In the problem I am suppose to use the wave equation to solve it. I assume 1D plane wave duct, u(x,t) = 1/(rho*C)*real((Aexp(ikx)-Bexp(-ikx))exp(iwt)) where C is the speed of sound, u is the velocity, p is the pressure, w is the angular frequency, t is time, rho is the density, and both...

Hello, why an electromagnetic signal propagate as wave? Wouldn't be more normal that electron travel in a beeline? Thank you.

Homework Statement I want to measure the size of my back yard. I estimate that I can measure the length and width of the yard using a tape measure to an accuracy of 0.05m. I find that the length of the yard is 8.6 m and the width is 7 m. Calculate the perimeter of the yard and its...

A while back, one of my undergraduate physics professors gave an argument for why the uncertainty in a function or quantity F is given by \Delta F = \sqrt{^{N}_{i-1}\sum(\frac{\partial F}{\partial x_{i}})^{2}(\Delta x_{i})^{2}} He argued to think of a right triangle and think of...

Why do transverse waves propagate through solids , while logitudinal waves can only propagate through fluids?? I'm still confused about this

Hello, Given a 3D gaussian beam incident on a lens at an angle relative to the optic axis, with phase and amplitude on the incident surface known, what is the simplest way to find the phase and the amplitude after propagation through the lens? Sasha

Would gravitational waves propagating through space-time at the speed of light be affected by the curvature? Or are they independent? Why does the spinning of a binary pulsar cause a gravitational wave when there is no change in mass other than the loss of photon energy? Doesn't this object...

A steel wire of radius 0.65 mm is subject to a tension of 11.29 N. Steel has a volume mass density of 7800 kg/m3. Find the velocity of propagation of transverse waves on this wire, in m/s. I found the cross sectional area of the wire but I am not sure where to go from there. I know I need...

This is an issue I am running into at the beginning of my physics course. Homework Statement Given distance and time in minutes, calculate the time in hours (part of a larger average velocity question) and graph over 170minutes. Include error bars in the graph Homework Equations...

When reading some papers in robotics, I found two different ways of the velocity screw and velocity propagation. This is one description of calculation a point's velocity in the paper "A tutorial on Visual Servo Control", we say paper A. The author said: The rotation acts about a point...

Does anyone know the Lagrangian for the propagation of light in curved spacetime? I'm disappointed to discover that I don't actually know how to compute the action for a given null curve.

I am modelling a radio wave propagation simulator for a Wifi at 2.4 Ghz. I know that the refracted index of glass for light is around 1.5, how do I translate this to a 2.4 Ghz radio wave. And what about other materials, such as concrete, brick wall etc. Thanks.

Hi! Here is my problem: there is a star, for which we know the distance, d=21.2 pc, the measurement error is delta_d=1.8 pc. The question is that how far should we put this star, so that the following equation would be true: d/delta_d = 3? The teacher told me to use two formulas...

Could you possibly comment the following statement: 'Heat propagation is a semi-deterministic process in that its future is determined by its present but not by its past.' Is heat propagation a violation of the determinacy and reversibility of the laws of classical mechanics? Thanks

Hello, there is a subject of wave propagation and collapse that has plagued me for some time, and although i must have heard about it, my memories are probably skewed ( i studied EE and had high frequency, physics of materials and nuclear/quantum physics sometime in 1970s :) as subjects). In...

I know 75ohm CATV coax is anything but ideal for 2.4GHz, but I am still curious as to how far these signals will travel upstream through the existing local cable network (splitters, etc) laid by the cable company, and if they could be transmitted between adjacent houses on a street. Example: an...

Hello If I entangle to atoms in close proximity to each other, is there any way I can separate these atoms by a large distance and maintain their entanglement? Thank you.

In the same sense that sound waves propagate through air, water waves through water, light through spacetime, what medium does the de broglie wave propagate through? Also, how could one detect such a disturbance in this medium without measuring the particle itself? (i.e. you can see the wake of...

Homework Statement This is about experimental physics. I have a value of resistance R=9000 \pm 1000. Then I had to do the following calculation: \frac{40000}{9000}=4.44 \ \Omega So, I'm not quite sure how to calculate the final uncertainty from my uncertainty \sigma = \pm 1 \ k\Omega...

I'm having trouble understanding why only certain angles of propagation can transmit down an optical fibre. My lecturer produces this formula for the allowed angles: \sin \theta = p \frac{\lambda}{2dn} where \theta is the angle of the ray from the optical axis \lambda the wavelength of light d...

I recall that when in school, teacher said that during a wave propagation, be it the longitudinal wave (like sound wave) or transverse wave (like water surface wave), particle in every position only oscillate along its equilibrium position, and will not experience translational motion. i.e., if...

Hi everyone, I have a specific question regarding the nature of electromagnetic waves. I understand he basics of EM waves (frequency, amplitude, wavelength, etc.) and that 'it' is a pair of oscillating fields; one electric and one magnetic, perpendicular to the direction of travel. What I...

Hi Guys, I came across this article by Jikang Chen and it is of importance to me to know what measure of credibility this concept holds in the general physics fraternity. I do not have the background to make sense of the mathemetics or physics cited. I would appreciate your comments. The...

Okay, so I have an assignment for uni and my friends and I need to work out some info to fill out an excel document, however we're not sure exactly what it is that we're looking for. The section we're stuck on, as the title suggests, is the 'error propagation' section. Are we looking for the...

Homework Statement I was wondering if I did this right. I have to take the partial derivative of the equation below. N is an integer number having no uncertainty.Homework Equations Fc= (4pi2mn2r)/(T2)The Attempt at a Solution This is what I got as an answer with first respect to m, then r, then...

my question concerns electromagnetic (EM) wave propagation. consider a two layer medium where the first layer has constant conductivity $\sigma_0$ and the second layer constant conductivity $\sigma_1$. If a EM wave propagates from the first medium into the second one boundary conditions have...

The intensity (W/m^2) of an electromagnetic wave from an ordinary antenna decreases with the square of the distance from the emitter (in the far field.) Is the same true for a laser beam?

So if a single photon is emitted and it travels as a wave, then it should lose its energy by distance squared. But how can it possibly do it? -its a single photon, so its intensity cannot really change, can it? What - you will have a half of photon? What does that even mean? How can it be like...

huy there! everyone says that light has wave particle duality. it means light is a wave and also consists of a particle. now, wave is a disturbance in a medium. but, we know that light can travel without a medium. then why do we say it is a wave? (i know that it is a non mechanical wave then why...

I've read in various places on the web and on this board discussions regarding subwavelengths, but I still can't fully comprehend how it's possible for an EM wave to transmit through an aperture and\or encased waveguide that is smaller than the given EM wave's wavelength. I've read about...

Dear Friends, I am new to this forum and I am not sure whether I am writing my Query in the correct section or not...If not Kindly guide me where to post this... I am confused about what are normal modes of propagation in isotropic or anisotropic media?? or How one can define Normal modes...

I am trying to figure out how the TEM wave looks like and how it propagate outward. Attached is a pdf of a drawing with only the solenoid and show the winding that the current is flowing in CCW and a reference. Also I draw a loop with one resistor and show the induced current and the polarity of...

Please confirm the direction of propagation for me. If the E field is defined as: \vec E \;=\; \frac{\mu_0 k}{2}(ct-|x|)\hat z 1) With this equation, the direction of propagation of the E field in both + and – x direction even though the \vec E = \hat z E_z? 2) The E field is not...

Hi All, In wave theory, we learn that Huygens' principle apply and that every point in a wave front acts like it was a source. According to this, it seems that from a given wave front we would see, after some small time interval, not only the the propagated wave front but another one...

Homework Statement Using the third and fourth of Maxwell’s equation in integral form, show that a plane polarized electromagnetic waves propagates in accordance with the generalized wave equation. Determine the velocity of light in terms of the permeability and permittivity constants...

Homework Statement A loudspeaker at the origin emits sound waves on a day when the speed of sound is 340 m/s. A crest of the wave simultaneously passes listeners at the{xy} coordinates (43 ,0) and (0,33).What are the lowest two possible frequencies of the sound? Homework Equations v(sound)=...

I was looking into propagation of EM waves, and it appears there is an overlooked nuance here. It is often said that EM-waves are self-propagating because a change in the E-field causes a magnetic field nearby, so a constantly changing E-field [i.e. a "vibrating" field] causes a constantly...

A beam of unpolarized light falls upon a polarizer which polarizes the light in e.g. x - direction. After that polarizer, we put another one which polarizes it along the y - direction. Of course, no light is transmited. Now we put a third polarizer between the first two, so that the third one...

hi, Could anyone help me the following question? I am reading light transmission through a slab of air (at the ambient atmosphere). My question is: How much light is transmitted without hitting any air molecules? In details: An incident light beam propagates through a slab, of some...

Homework Statement Assume a piano has 100 different notes from the lowest to highest. We go up from note to note by the same frequency ratio, say starting at 20 Hz. Assuming that the lowest frequency excites the basilar membrane, 30 mm long, at its end, and that this represents a quarter of a...

Homework Statement A pulse train of Gaussian shaped pulses travels in a single mode fibre. The separation (T) of the pulse centres is five times the temporal width (\Delta \tau) of an individual pulse i.e. T=5*\Delta \tau. The dispersion of the material is D=200ps/nm/km. L=0.1km, n plastic =...

Homework Statement A plane monochromatic wave propagate in an infinite ferrite medium which is magnetized to the saturation at an angle theta to a constant magnetic field. The magnetic permeability of the ferrite is given by the tensor of the form: mu_ik = ((mu_a, -i mu_b, 0),(i mu_b...

I have already turned this lab report in, but I am sure this will come up in the future. I just want to insure that I am doing it correctly. Homework Statement We did an experiment on the photoelectric effect. We found the negative voltage plateau and took readings of the photocurrent...

I was taught that Huygens's principle is an accurate description of the way light propagates. Something like: "All points along a wave front can be modeled as point-sources for new waves having the same phase and frequency." This appears to be a good model to explain phenomena such as...

I'm working my way (slowly) through Landau & Lif***z Classical Mechanics. I'm finally nearing the end of chapter one, and although I hit another stumbling block, I think I've got it now. If anyone has the time to check my reasoning, I'd be grateful. I will quote the passage that was confusing...

Homework Statement I'm trying to calculate the velocity of propagation of a RG58 cable that is 0.5m long. It is connected to a pulse generator that passes pulses through the cable. The cable is connected to an oscilloscope, which plots the pulses. The period of the pulses are 5 microseconds...

What is the difference of a magnetic and nonmagnetic medium? And how does it affect wave propagation on these mediums?