Propagation Definition and 487 Threads

I read that capability of electromagnetic signal propagation depends on material or conductor from which it is passed... I want to know How does it effect?... What are characteristics of conductors that result in attenuation for certain frequencies?

Dear topic mates! I'm an electric engineer and physicist student from Hungary. I looking for description of the spherical shock wave propagation in liquids. I need a formula which give the relationship between the propagation velocity and time. Additionally, I wonder the pressure at the...

Homework Statement Consider the multi-path propagation phenomenon discussed in class. Assume the signal from a sender takes 4 paths to arrive at the receiver, and the delay along each path is 3, 6, 9, 21 (in micro-seconds), respectively. Each symbol is 1 bit long. Two symbols can be...

Homework Statement A wave takes 4s to travel form one end of the string to the other. Then the length is increased by 10%. Now how long does a wave take to travel the length of the spring? Homework Equations v = sqrt ( FL/m) F = -kx The Attempt at a Solution If the original...

This came up at mythbusters, a question about the propragation of currrent from a switch that is a long distance from a DC power source. Assume the wires are sufficiently large (capcitance wise): 1 mile long wire connected to positive terminal of DC power source at one end, open switch at...

Homework Statement we are trying to find the x -component of a velocity vector (V*cos\theta) our uncertainty for the velocity is +-.0003 and for the and it is .5(in degrees) how do we propagate the error for this v=.048 while \theta =27 degrees Homework Equations The Attempt...

Homework Statement Given that a puck's velocity is speed v at an angle \theta (measured in radians) with the x-axis, we know that the puck's x-velocity is v\cos(\theta). Given the error in v is \sigma_v and the error in \theta is \sigma_\theta, what is the resulting error in the puck's...

heys, sorry I didn't know where to post this hopefully I will get some responses. well, I had a set of differential equations which I solved using MATLAB and got plots as traveling waves(t=1 to 10). basically, I need to find the velocity at which the wave is propagating and I have no...

1. Homework Statement Estimate the absolute and relative standard deviations of the following calculations. The number in parentheses is the standard deviation of the preceding value. a) z=5.64(s=0.14)*log(138)(s=3) 2. Homework Equations Sx/x =SQRT((Sp/P)2+(Sq/q)2+(Sr/R)2...

Homework Statement Estimate the absolute and relative standard deviations of the following calculations. The number in parentheses is the standard deviation of the preceding value. a) z=5.64(s=0.14)*log(138)(s=3) Homework Equations Sx/x =SQRT((Sp/P)2+(Sq/q)2+(Sr/R)2 Sx=0.434(Sp/P)...

I have a perfectly conducting circular waveguide. I want to calculate the time-averaged Poynting vector of a circularly polarised TE mode, ie: H_z = H_0 J_{n}(\rho \chi)e^{in\phi} Where \chi is the appropriate eigenvalue. My result for <S> implies helical energy flow; it has a z...

Homework Statement Given that f=\frac{\bar u \bar v}{\bar u +\bar v} show that e_f=f^2({\frac{e_u}{\bar u^2} + \frac{e_v}{\bar v^2}) where e refers to the error. ok so I added up the fractional uncertainties Homework Equations The Attempt at a Solution and I got this...

Hello everyone, a wave propagates at a speed (group of phase speed), less than the speed of light, no matter what type of wave we are dealing with (electromagnetic, mechanical,...). Why is infinite velocity characteristic of a diffusion process? What does that mean? For something to...

Homework Statement Hi everyone, I'm having some homework trouble, and am hoping you can help me out. Here's the question. QUESTION: Using the propagation method for calculating uncertainties, calculate the absolute, relative, and percentage uncertainty for the volume of the cylinder and the...

Homework Statement When an EM wave propagates, the E and M field at a point are perpendicular. If E and M at a point are NOT perpendicular to each other, can it be that an EM wave is passing through that point?Homework Equations The Attempt at a Solution Consider a linearly polarized light...

So - if the Sun were to be suddenly altered in a unlikely collision, The Earth would continue it's curved path for about eight minutes before we all became somewhat alarmed.. There is a excellent home-brew demonstration of gravity effect using a torsion balance, done in a University basement...

With: wavelength = 4 meters frequency = 30 cycles/sec period, T, = .033 sec/cycle wave propagation velocity = 120 m/s wave number ,k, = 2pi/wavelength = 1.57 radians/meter angular frequency, w, = 2pi/T = 188.5 radians/sec phase velocity = w/k = 120m/s In the above propagation...

Homework Statement wavelength = 3m frequency =25 cycles/sec period T = 1/frequency = .04 sec/cycle wave propagation velocity =75 m/s wave number K = 2pi/wavelength= 2.09 radians/m angular frequency w = 2pi/T = 157 radians/s phase velocity Vp = w/k = 157/2.09 =...

Can anyone validate that phase always decreases in the direction of propagation of wave? Also if i have a sonometre wire in which i develop a transverse wave using a tuning fork and then i immerse the weight into water i.e change the tension, will the frequency also change? I mean frequency...

Hello, my friend: Recently, I encounter a MATLAB program problem on the propagation of the soliton in dielectric . I find that many people use a beam propagation method ( split-step fft ) in order to simulate this procedure. But I cann't get incorrect result. I am eager to...

I'm running a simple limiting case of a simulation with the expression: exp(-i*H*t), where H is the hamiltonian, in this case a 2x2 matrix of zeros. Should this evaluate to 0, or to [ 1 1 ; 1 1] ? Right now my sim uses the latter, which I'm sure is wrong. What do you think? Thanks in...

Hi! Didnt know where to post this.. I was trying to fresnel propogate a spherical beam using the formula U(x,y)=\frac{e^{jkz}e^{\frac{jk(x^{2}+y^{2})}{2z}}}{j\lambda z}\int^{\infty}_{-\infty}\int^{\infty}_{-\infty}{U(\xi,\eta)e^{\frac{jk(\xi^{2}+\eta^{2})}{2z}}}e^{-j\frac{2\pi}{\lambda...

I have a couple of questions about single slit diffraction. It's not a homework exercise - just a conceptual problem. Here it is (with some introductory comments)... I understand that the diffraction pattern from a single slit is the modulus squared of the Fourier transform of the aperture...

Homework Statement If a wave is started up a long rope hanging from the ceiling, it will not climb at constant velocity. Why? Will the wave be traveling faster or slower at the top than the bottom? (Hint: Is the tension of the rope a factor?) Homework Equations v=square root...

Howdy, I'm no physicist, but I am a scientist by trade and some basic physics questions always bug me because I don't have any bases of understanding of the concepts. I apologize if these questions seem a bit abstract: Suppose an event occurs that causes the emission of EM radiation (for...

I am trying to determine the critical crack length of a part using finite element analysis. The software I am using (ABAQUS) has the ability to perform fracture analysis. I model the part, create a crack, and ABAQUS will output the stress intensity factors (modes I, II, and III) and contour...

Hi All, Em waves propagate in varying ground conditons, in the ground the velocity of em waves is reduced since it is dependant on the relative dielectric permittivity, the realtive magnetic permiability & electrical conductivity. This will more than likely make no sense at all? My...

Homework Statement 1) I'm using a 4 bit carry lookahead adder to build a 8 bit parallel adder. I'm to calculate the maximum propagation delay time, assuming each gate introduces a unit time of propagation delay. I'm assuming not carry lookahead generators. Would it just be 8 units of...

What must be present for the propagation of a mechanical wave?

Hi! Can some one give me a link where i can find details about finding the velocity of propagation of a mechanical wave in a solid? (i think this wave must be a transverse one)

Hi, I've been trying to reproduce the output of an analytical machine here at work by doing the calculation myself in Excel but I can't get the error to match. Perhaps I am propagating the error incorrectly... The calculation is z = 2^(x-y) The values are: x = 24.96 y = 25.98 and...

Homework Statement how to find the speed and direction of propagation from the wave equation? Homework Equations y(x,t)=Aexp{B(x-ct)^2} The Attempt at a Solution

Say something is a value +/- .05. What happens when you take the inverse of the value? For example, 30 V +/- .05 V. 1/V...what would the error be?

Homework Statement Calculate "f" and its uncertainty, watch the units, show all work. Homework Equations f(x,z)= z/x x=100.5(+ or -) 3.8 cm y=71(+ or -) 1 s The Attempt at a Solution ok so i know that to find uncertainty i have to use the equation delta f(x,y)=df(x,y)/dx...

Homework Statement I was looking through my notes when I saw the following expression of a plane wave represented as a phasor A_{0}e^{i(\vec{k}\cdot\vec{r}-\omega t)} Now I can certainly understand a plane wave propagating along a given coordinate axis say, x or z, and the phasor...

I am concerned about getting the same length to all RAM chips (the output is equidistant to all inputs of the different chips) I heard somewhere that a rule of thumb is that you get .18 nanoseconds of time delay for every inch of tracing. Is this accurate? Is it safe to use this when...

err probably skin too many q's but anyway... what type of waves are made from naturall sources?eg then sun etc...are theren any square waves...im just wandering ifn there's any weirdness or differences when using square waves as a carrier wave in transmitting...if u know any good info sources...

Consider some material object, more or less rigid, with two ends, A and B, like A---B It is at rest at a point in time t_0 in my reference frame. Now I kick it a bit, i.e. I apply some force for a limited amount of time at A in the direction of B. After the kick, the whole object has a...

Homework Statement 2.Explain in your own words what Einstein means by “the principle of relativity”, and why it seems to be incompatible with the theory of electromagnetism (or “the law of propagation of light”). Homework Equations Not an equation but Einsteins answer can be seen here in...

How fast does the magnetic field propagate from a magnetic source? In a vacuum versus through air, etc.? Does the magnetic field propagate faster from a stronger magnet? What is the makeup of a standing magnetic field? Electromagnetic waves or a force field more similar to gravity?

Given Klein-Gordon equation for a particle of mass m in covariant notation \left[ \partial_{\mu} \partial^{\mu} + \frac{m_0^2 c^2}{\hbar^2} \right] \phi = 0 show that the solution preserves causality, i.e. signals have a velocity not higher than c. HINT: You can build up a quantity...

Hi all, I was wondering whether someone can help/guide me. I am doing a project that involves sound propagation in solids. Basically, I have two microphones placed on a surface (say a piece of wood). Then, when a person taps on the surface I can detect the tap and determine the amplitude of tap...

Hi all, I was wondering whether someone can help/guide me. I am doing a project that involves sound propagation in solids. Basically, I have two microphones placed on a surface (say a piece of wood). Then, when a person taps on the surface I can detect the tap and determine the amplitude of...

Homework Statement this is regarding propagation of error for a lab i did: we measured the amplitude of a damped harmonic oscillation over a time period, taking amplitude measurements every 1 second for 14 seconds. when graphed (by excel), the plot has the form of y = Ae^(-gt), where A is...

I would like to know how heat would flow in a material being struck by sunlight in vacuum. The usual examples of Fourier heat equation always uses boundaries with fixed temperature or under convection. How do I calculate this when the surface is absorbing and emitting radiation according to...

In the beginning of their book, Peskin & Shroeder say that replacing non-relativistic energy p^2/(2m) with the relativistic one \sqrt{p^2 c^2 + (mc^2)^2} does not remove infinite propagation speeds given by the propagator \int\frac{d^3p}{(2\pi\hbar)^3} e^{-i(E_p t - p\cdot(x-y))/\hbar} Does...

Ok, this isn't a homework question -- more out of curiosity. But it seems so trivial that I hate to post it under "General Physics" We all know the standard formula for error propagation: \sigma_f = \sqrt{\dfrac{\partial f}{\partial x}^2 \sigma_x^2 + \dfrac{\partial f}{\partial y}^2 \sigma_y^2...

Hi, I wasn't really sure whether to put this post under Physics or Engineering. I was just wondering whether someone can gimme some help or info or guidance... I am currently working on a project in which I am using the FFT (Fast Fourier transform) algorithm. In a nutshell, I am trying to use...

Suppose we have a stretched string, with one of its end fixed at a wall. Now if we just jerk the string(up and down), we get a mechanical wave, i.e. the disturbance caused by us at one end of the string travels to the other end. Now the question is, how and why does the disturbance travel...

Hello, I'm familiar with the common calculus approach with partial derivatives to evaluate error propagation in calculations with random variables. However, I'm looking for a way to derive the classic formula with the sum of fractional errors squared: {\left(\frac{\Delta Z}{Z}\right)}^2 =...