Modes Definition and 243 Threads

After the first explanation of superconductivity by Bardeen, Cooper and Schrieffer, it was for several years a matter of concern to render the theory charge conserving and gauge invariant. I have been reading the article by Y. Nambu, Phys. Rev. Vol. 117, p. 648 (1960) who uses Ward identities to...

Homework Statement Consider the CO2 molecule as a system made of a central mass m_2 connected by equal springs of spring constant k to two masses m_1 and m_3 a) set up and solve the equations for the two normal modes in which the masses oscillate along the line joining their centers (the...

1. Homework Statement Someone studying a dynamical system in another field of science tells you that when they attempt to model the experiment they’ve been examining they obtain the following set of coupled ordinary differential equations. \dot{x}= -Ax + By \dot{y}= -Cx In what follows you...

say a system has 3 modes. under free vibration does it vibrate in all the modes all just one mode? why. also if we apply a either a impulse or pulsating force to the system, in which modes the system is going to vibrate and why? thanks.

A string with one end fixed as U(x=0,t)=0. The other end is attached to a massless ring which moves frictionlessly along a rod at x=L a) Explain the boundary condition at x=L should be d/dx U(x,t) = 0. b) Find the normal modes for the wave equation d2/dt2 U(x,t) = c2 * d2/dx2 U(x,t) with the...

Homework Statement Consider a mass M whose motion is confined to a flat, smooth two-dimensional surface. Label the locations in this surface using the Cartesian coordinates (x, y). The mass is attached to two identical springs, each of length ℓ and spring constant k. One spring has one of its...

Homework Statement A block of mass M can move along a smooth horizontal track. Hanging from the block is a mass m on a light rod of length l that is free to move in a vertical plane that includes the line of motion of the block. Find the frequency and displacement patterns of the normal...

Homework Statement A uniform rod of length a hangs vertically on the end of an inelastic string of length a, the string being attached to the upper end of the rod. What are the frequencies of the normal modes of oscillation in a vertical plane? Answer: \omega^2 = (5 \pm \sqrt{19})g/a...

Why is the lowest order TM and TE mode TM11 and TE10(or TE01)? What is the physical meaning of the different orders of the modes? Thanks.

Homework Statement In an experiment to measure photon statistics of thermal light, the radiation from a black-body source is filtered with an interference filter of bandwidth 0.1 nm centered at 500 nm, and allowed to fall on a photon-counting detector. Calculate the number of modes incident on...

An anchored string is a simple modification of a vibrating string. We imagine a sideways restoring force applied to a vibrating string. The sideways force per unit length is proportional to the displacement of the string. This additional force gives the string the the same dispersion curve as...

Let's say you want to quantize the EM field in a system with real permittivities and permeabilities. You expand the fields into a superpositions of their classical modes, and note that pretty much every real spatial mode requires two real conjugate canonical variables to describe its time...

I am going over some notes and am trying to fit some pieces together. For some reason I keep confusing myself as to what exactly a "mode" is. Is a mode a wave? or a frequency? Also, how does a mode relate to the degrees of freedom for a particle in a system? Thanks!

I don't know if this the right forum to post this question but i can't figure out which forum i should use:confused: here is my question What are the modes in Oscilloscope? i did google search but couldn't find clear answer for my question. thanks

Hi.. I have a question about natural fvibration. Every object has natural frequency and modes of vibration. Let us consider a simple cantilever beam for our discussion. and Let's say its first 4 modes of vibration are at 3, 6, 10 and 20 kHz respectively. (I made up these frequency values)...

Hi everyone, I was wondering if someone could please explain to me the concept of waveguiding, coupling/coupled, and guiding mode. Here is an application of these terms: The photons emitted in the active region of OLEDs are coupled into three types of modes: direct transmission into...

Homework Statement A particle P of mass 3m is suspended from a fixed point O by a massless linear spring with strength alpha. A second particle Q of mass 2m is in turn suspended from P by a second spring of the same strength. The system moves in the vertical straight lie through O . Find...

I'm looking for an in depth and comprehensive treatment of the theory of normal modes; any suggestions?

Let's take for example the decay K+ -> pi+,pi0,gamma This can proceed via direct emission or inner bremsstrahlung. I have questions for each of these modes 1. For inner bremsstrahlung, it is a final charged product that radiates, correct? In this case the pi+. What is causing the...

[SOLVED] Springs, Normal Modes, and Center of Mass coordinates 1.) Problem The problem of the linear triatomic molecule can be reduced to one of two degrees of freedom by introducing coordinates y_{1} = x_{2} - x_{1}, y_{2} = x_{3} - x_{2}, and eliminating x_{2} by requiring that the center...

If I have a finite boundary, say of length L. Is it possible to demonstrate that if I were to allow all possible CONTINUOUS values of a wave to exist (with unit amplitude) then deconstrutive interference destroys all waves except those with wavelength: k=\frac{n\pi}{L} Where n =0,1...

Hello I'm looking for a list,as complete as possible, of decay modes and their probabilities, for all known subatomic particles. I've been googling, but found only bits and pieces. Perhaps someone knows a place on internet, or has found a free document to share, or anything like that thanks

I need a reference describing the possible decay modes of the Higgs. Can anyone recommend any books or websites?

Homework Statement hey, this is my first time using this forum and was wondering if i could have some help with this normal modes question. suspended from a ceiling is in order: a spring of spring constant (k_{2}), a mass (m), a spring with spring constant (k_{1}), and another mass (m)...

Homework Statement What is the difference between a mode and a node The Attempt at a Solution I am not really sure, because they seem exactly the same to me. Any help would be much appreciated!

I am trying to determine some failure modes of strain gauges and the means of accomplishing some of them. Things like loose leads, debonding, physical damage, thermal effects, doing things that cause saturation. I am looking for ideas of what other failure modes are and ways to accomplish...

I Have a question that is bugging me because I can't get the answer out here's the question: A uniform rod of length a hangs vertically on the end of an inelastic string of length a, the string being attached to the upper end of the rod. What are the frequencies of the normal modes of...

I Have a question that is bugging me because I can't get the answer out here's the question: A uniform rod of length a hangs vertically on the end of an inelastic string of length a, the string being attached to the upper end of the rod. What are the frequencies of the normal modes of...

[FONT="Georgia"]Homework Statement Discuss the motion of a continuous string when the initial conditions are q'(x,0) = 0 and q(x,0) = Asin(3πx/L). Resolve the solution into normal modes. Show that if the string is driven at an arbitrary point, none of the normal modes with nodes at the driving...

Hello all, if I have incoming radiation from a blackbody source filtered to a bandwidth of 0.1 nm and centered at a wavelength of 500 nm, why is the number of modes in this light not equal to the density of photon states times the bandwidth? I.e why isn't it \text{number of modes} = g(\omega)...

Can anyone point me to an online resource which gives details - and applications - as to when one should model an optical field using TE and TM modes, and when it's OK to use TEM modes. Cheers. edit: should've stuck this in the normal physics forum... mods please move... More specifics...

I have just been solving some systems of ODEs to find the nomal mode solutions. Something about it has been bugging me though. In a simple case where we have a system of two linear ODEs representing a two-mass spring system, we assume that the solution is a normal mode and so find a general...

Hello, I'm preparing for my condensed matter exam and I'm trying to solve problem 3a) of chapter 22 in Ashcroft & Mermin. The problem is basically to prove that the dispersion relation of a diatomic linear chain will reduce to the monoatomic one when the coupling constants are equal...

Hi, I have a few questions about Sonometers which I've attempted to think through - though I may be missing something. Perhaps someone can fill in any gaps for me? If I was to be asked why only 'discrete modes' of vibration can exist for a sonometer, is it enough merely to talk about the...

Hi, Did some one calculate the dispersion characteristics of TM volume modes in layered magnetized semiconductor structure?

This might be a bit to specalised for some of you, but i am trying to calculate the number of modes that light can propegate in a material. The question is as follows Consider a cavity that is a cube with the side length a = 1mm filled with water (refractive index(n) 1.33). Calculate the...

from C.Z. Tan, Optical interference in overtones and combination bands in \alpha-quartz, Journal of Physics and Chemistry of Solids 64 (2003) 121–125. [1] M. Born, K. Huang, Dynamical Theory of Crystal Lattices, Clarendon Press, Oxford, 1988. [2] C. Kittel, Introduction to Solid State...

Trying to do some reading on squeezed electric field modes in accelerated frames, and it's a bit much. Anyone have any suggestions as to some literature to familiarize myself with before i go any further? Thanks Phil

I have a book here that says that the number of normal modes is equal to the number of degree of freedom of a system. I'm wondering if this applies to just about any system or only to systems in which every coordinates can oscillate harmonically. The question is not very well formulated, so I...

Dear friends, I'm having trouble with this problem, I don't know if I'm doing it right, I'd be grateful if you could advice me. Two discs, each of mass M and radius R, are supported with equal separation along a slender rod to which they are rigidly fastened at their centers as shown in...

urgently need help: localized modes in linear chain and localization effects Hello everyone, it is great place you have here, hope I can learn a lot from you I am doing some readings and there are couple of concepts that I havent been familiar with and if you spend a little time to help me...

Could someone please tell me how I could calculate the vibrational modes of a solid sphere, or where I could find this information? I want to make the calculations for a sphere with a unit radius.

When I was viewing some photos about rocket engines (spatial ones), I wondered me in what mode is operating the nozzle in the normal working.I am going to try to explain it better (do not show me a strange face yet). I studied the different exhaust modes of a convergent-divergent nozzle...