Coupled Definition and 414 Threads

  1. S

    Coupled differential equations for charged particles

    Hello, I wanted to study the behaviour of electrons in a spatially bounded system. I want to have a larger number of electrons, but I took 3 to start with and arrived at this system of coupled equations: \begin{align}\begin{bmatrix} \mathbf{\ddot{x_{1}}}\\ \\ \mathbf{\ddot{x_{2}}}\\ \\...
  2. B

    Finding Solutions for Coupled ODEs with Constant Parameters

    Hello :)I have a system which consists of two coupled ODEs for which I want to solve.F'' *(1/b²) - α²*F = Ra*(1/b³)*G G'' *(1/b²) - α*²G + Ra*(1/b²)*G = F'(1/b) In these two equations F(z) and G(z) both depend on z. b is a constant, Ra is the rayleigh number which I need to keep as Ra in my...
  3. D

    Solving Coupled ODEs with 4th Order Runge-Kutta Method

    Can a 4th order Runge-Kutta method be used to solve an equation of this form: dVx/dt = ωVy , where ω = constant. and Vx and Vy are the x and y components of the velocity.
  4. ognik

    Understanding coupled Runga Kutta derivation

    I understand Runga Kutta 4th order for use with a single ODE, but am not confident I have correctly derived how to apply RK4th to a coupled or 2nd order system. As example I have dy/dt=p; dp/dt=-4pi2y I recognize this as SHM with w=2pi so yes, I don't need RK to solve it, but I want to use...
  5. samjohnny

    How Do You Calculate Normal Modes in a Vertical Coupled Oscillator System?

    Homework Statement An object A with mass 3m is suspended from a fixed point O by a spring of constant k. A second object B with mass 2m is in turn suspended from A by an identical spring. The system moves along a vertical axis through O. Find the frequencies of the normal modes, and the...
  6. J

    Setting up an LRC series circuit with coupled coils

    Homework Statement I have been trying to set up an LRC series circuit where in place of an inductor we have a pair of coupled coils. My aim is to determine the resonant frequency in the circuit when the voltage across the resistor or the current in the circuit is at a maximum. I am using a...
  7. N

    Engineering Coupled RC circuits with AC current source

    Homework Statement Hi, I already asked a question close to this, but now I have different conditions. This is the circuit C_1 = C_2 \\ R_1= R_2 The current is an AC , and I would like to know the voltage at R_1 and at R_2 I made some progress but I do not really know hot to continue...
  8. N

    Engineering Solve Coupled RC Circuit: Find V1(t) & V2(t)

    Homework Statement Hello I want to solve the following circuit, I want to know how the voltage on R1 and R2 develop with time, It start at t=0 when there is no voltage in the circuit ( all V=0). Its a symbolic question, I need to show the equation. V1(t) = ? , V2(t) = ? The current is a DC...
  9. D

    Pendulum and spinning mass -- Coupled

    Homework Statement Imagine two masses connected to each other by a string. One mass sits atop a table, while the other mass dangles below the table, as the string is fed through a hole in the center. The configuration looks like this...
  10. topsquark

    MHB Coupled non-linear system of ODEs

    If you really want to know where this comes from I am solving the GR equations for a rectilinearly isotropic metric. In other words, I can express the metric as d \tau ^2 = -T(x) dt^2 + X(x) dx^2 + dy^2 + dz^2. (It may be simpler to use a cylindrical coordinate system, but the equations come...
  11. NATURE.M

    Coupled Oscillator: Solve 4.35 Homework

    Homework Statement Note this question is from Morin 4.35. The system in the example in Section 4.5 is modified by subjecting the left mass to a driving force Fd*cos(2ωt), and the right mass to a driving force 2Fd cos(2ωt), where ω^2 = k/m. Find the particular solution for x1 and x2. Just...
  12. J

    Help with coupled spring and pendulum system

    Homework Statement Given the system in the image below, I need to find the equation of motions for the coupled system. The surface where the block moves is frictionless. The red line is position where the block is at equilibrium. At equilbrium x1 and x2 = 0. After finding the equation of motion...
  13. R

    Help: Analytical Solution to Coupled ODE

    Hello , I tried to solve this coupled ODE but with no success Does anyone know if there is an analytical solution to this equation? my problem is with the first & the second equations the term g*f is the my biggest problem i think once i have the solution for g - the solution for h is...
  14. U

    Runge Kutta for 4 coupled differential equations

    Hi, I'm not a bright programmer , but I have to solve the fallowing equations: ##\frac{df}{dt} = \alpha f -\beta f + \theta g - (f+h)f## ##\frac{dg}{dt} = \psi f- \phi g## ##\frac{dh}{dt} = \xi f+ \mu h -\tau h + \epsilon w- (f+h)h## ##\frac{dw}{dt} = \nu h - \chi h## Where ##f(t)## ...
  15. J

    Piezoelectric coupled governing equations doubt

    Hi , can anybody make me sense of these equation on which i am striking my head for last 2 months. I am trying to understand piezoelectric effect. And in process of which i came to see so called strain based form of equations related to direct(Equation no.2) and reverse(Equation no. 1)...
  16. C

    Analytically solve second-order coupled ODE (damping term coupled)

    Homework Statement I need to (analytically) solve a system of coupled second-order ODEs: (A) \frac{du}{dt} - fv = \Omega^2x (B) \frac{dv}{dt} + fu = \Omega^2y where u = \frac{dx}{dt} v = \frac{dy}{dt} subject to the initial conditions u(t=0) = U and v(t=0) = 0. Homework Equations --- The...
  17. L

    Engineering Magnetic Coupled Circuit problem

    Q. In figure shown,if i1(t)=2tu(t) A,a voltage VCD =10u(t)mV is observed,then the placements of the dots and the value of mutual inductance M is what ? Sine current is entering the primary winding so i place a dot at "A",but where should put a dot in secondary winding.I do know that according...
  18. ranju

    Engineering Mesh Equations and Polarity in Coupled Circuits

    Homework Statement In the given attachment (supply has voltage v(t) , ) we have to write mesh equations .I am not getting how to decide the polarity of voltage across inductor ?Homework EquationsThe Attempt at a Solution There's nothing much to do.. The only thing I am doubtful about is the...
  19. M

    Coupled equation transformation

    can anyone help explain the mechanism of coupled equation transformation and when and how can i transform similar equations?
  20. gfd43tg

    Euler's method for coupled ODE's

    Homework Statement Consider the following pair of coupled first order ODEs \dot{y_{1}} = y_{2} with ##y_{1}(0) = 1## \dot{y_{2}} = -y_{1} with ##y_{2}(0) = 1## Use the Euler integration method with a step-size ##h = 1## and fill out the entries in the table below \begin{bmatrix}...
  21. S

    How Can I Write an Operator in the Coupled and Uncoupled Basis?

    Given a system of two identical particles (let's say electrons), of (max) spin 1/2 (which means the magnetic quantum number of each of the electrons can be either 1/2 or -1/2), how can we write the operators (total angular momentum, z-component of the total angular momentum etc.) (a) in the...
  22. J

    Coupled Antennas: Literature on Small Separation Distances

    Can anyone provide some literature on antennas spaced apart such that the spacing distance is much less than the wavelength? I am specifically interested in the mutually coupling behaviour as a function of small separation distances.
  23. hilbert2

    How Can We Describe a Coupled System and Heat Bath in Quantum Mechanics?

    Suppose we have a quantum system with one degree of freedom, ##x##, and a heat bath (possibly modeled by a large amount of coupled oscillators) with many degrees of freedom, ##q_1 , q_2 , \dots , q_n##. If the system and bath are coupled by some interaction, this is a simple model of a system...
  24. P

    MHB Solving Coupled ODEs: Analytical Solutions?

    Hello everyone, I have the following coupled ODEs (r\geq 0) g^2v^2f(r)h^2(r)+\frac{6}{r}f'(r)-3f''(r)=0, r^2h''(r)-4f^2(r)h(r)=0, with boundary conditions f(\infty)=1, h(\infty)=1. The other 2 boundary conditions are arbitrary. Also v and g are constants, that could be set to a fixed value...
  25. N

    Symbolic solve coupled second order differential equations

    Dear all, I have posted a similar question in another forum and the general consensus seems to suggest that it is not possible to symbolic solve a system of coupled second order different equation with damping (dissipation) and driving forces. However, I have found in many papers and books...
  26. E

    MATLAB Coupled 1st order differential equations in matlab

    Hello everyone I just want to ask if anyone could help me or at least tell me if it is possible to solve the couple equations using matlab I saw ode45 but that is for one equation only Thank uou
  27. C

    Understanding Coupled Spin Operators

    Trying to get my head around this one. Given that you can have a proton and an electron in a hydrogen atom for example, and they can create a singlet or triplet configuration, with spin 1 and spin 0 respectively. The total spin operator can be derived as: S^2 = (Se + Sp)^2 = Se^2 + Sp^2 +...
  28. G

    Coupled Oscillation attached at one end ?

    Homework Statement I'm supposed to determine the equation of motion of the two masses on the worksheet. I just need to start with that. Here is the problem statement: http://www.physics.udel.edu/~jim/PHYS211_14S/Homework%20assignments/Assignment%205%20-%20coupled%20oscillations.pdf...
  29. Runei

    Coupled driven and damped oscillators

    Hello, I'm trying to analyze a system of elastically coupled oscillators, whose masses are all the same, using Fourier expansion. So the differential equation I am looking at right now is of the form m\frac{d^2\hat{y}_k}{dt^2} + \gamma\frac{d\hat{y}_k}{dt} - \kappa\Delta^2\hat{y}_k =...
  30. T

    How to write coupled mode equation of a given structure

    Recently I am reading the papers in the field of PT symmetry systems. What I am confused is that in these papers, authors directly write out the equations describe the dynamics of the given systems( For example, in this paper http://arxiv.org/ftp/arxiv/papers/1103/1103.3389.pdf , authors put...
  31. Ravi Mohan

    Solving second order coupled differential equation

    How do we solve a system of coupled differential equations written below? -\frac{d^2}{dr^2}\left( \begin{array}{c} \phi_{l,bg}(r) \\ \phi_{l,c}(r) \\ \end{array} \right)+ \left( \begin{array}{cc} f(r) & \alpha_1 \\ \alpha_2 & g(r)\\ \end{array} \right).\left( \begin{array}{c}...
  32. A

    Coupled differential equations

    A bit related to my other topic but here goes: I have the set of differential equations: x1' = a-ax1-ax2 x2' = b-bx1-bx2 What is the solution to such a set? I could google systems of differential equations, but that turns up large texts on the theory. I just wonna know in a few lines...
  33. E

    Three Disks Coupled by Two Belts

    Homework Statement The figure below shows three rotating, uniform disks that are coupled by belts. One belt runs around the rims of disks A and C. Another belt runs around a central hub on disk A and the rim of disk B. The belts move smoothly without slippage on the rims and hub. Disk A has...
  34. A

    Solve Freq of Coupled LC Circuit with Inductor

    Homework Statement I have to find the normal frequencies of a coupled LC circuit. However, this LC circuit is coupled by an inductor, not a capacitor. __|C|________|C|__ |...|...| ^I(1)...|...^I(2) |...|...| {L}...{L'}...{L} |...|...| |...|...| -------------------- I'm sorry, I didn't have a...
  35. B

    Radio waves emitted by an inductively coupled power transfer system

    I would like to know if a a inductively coupled power transfer system also emits electromagnetiv waves. The system contains of two inductance coils one generating the magnetic field with AC, the other picking up the magnetic energy and transforms it into an AC, also. The current frequency is...
  36. T

    Found a cool Non-autonomous Coupled System of ODEs

    By a fortuitous mistake in copy/pasting, I happened across this system. It exhibits very chaotic behavior for some initial values and spiral-like shapes for others. (About a 70%/30% split, respectively.) x'=cosy+sint y'=sinx+cost Here's an album of it plotted from t=0 to 1000. The titles of...
  37. J

    Coupled 2nd order diff eq's (Bessel functions?)

    I have derived these pair of coupled diff equations for U_1 (r) and U_2 (r): r^2 \dfrac{d^2 U_1 (r)}{dr^2} + r \dfrac{d U_1 (r)}{dr} + r^2 U_2(r) = 0 and r^2 \dfrac{d^2 U_2 (r)}{dr^2} + r \dfrac{d U_2 (r)}{dr} - r^2 U_1(r) = 0 Or written in matrix form (r^2 \dfrac{d^2}{dr^2} + r...
  38. S

    Capacitively coupled RLC circuits

    Homework Statement Given a set of two capacitively coupled RLC circuits where each has a capacitor C and they share a coupling capacitor C^{'}. I'm trying to find nice organized material that will explain the various relevant coefficients\concepts like QF, bandwidth etc. in relation to the...
  39. G

    How Do Coupled Pendulums Behave When Connected by a Spring?

    Homework Statement Consider 2 pendulums with the same length L, but 2 different masses Ma and Mb. They are coupled by a spring of spring constant k which is attached to the bobs (the masses). a) find the equations of motion b) find the frequencies and configurations of the normal modes...
  40. D

    How does the electric field get removed in crystal oscillator circuits?

    Hello folks, I've been trying to understand how crystals work in crystal oscillator circuits. I understand the piezoelectric effect to the following extent: If we apply an electric field to the crystal it will deform and when the field is removed, the crystal will generate an electric field...
  41. P

    Solving two coupled PDE from a quantum problem

    Hello Guys. I have to solve two coupled PDE coming from a quantum physical problem, which possesses a cylindrical symmetry. They look like this \left\{-\frac{i\hbar}{2M}\left( D^2_\rho + \frac{1}{\rho}D_\rho + D^2_z - \frac{L_z^2}{\hbar^2 \rho^2} \right) + \frac{M\omega^2_\rho \rho^2}{2} +...
  42. L

    How Do You Calculate Torque in a Gearbox-Flywheel System?

    Homework Statement Gearbox coupled to a flywheel. The gearbox I 92% efficient and the output shaft rotates at 5 x the speed of the input. Flywheel mass is 50kg, 0.75 m radius and is to accelerate from 0 to 300 rpm in 60 seconds. Calculate Input torque and holding torque (value and...
  43. M

    Kinetic Energy in terms of Conjugate Momenta

    Thanks if you take the time to read this. Homework Statement Homework Equations The Attempt at a Solution The problem I'm getting is that I'm not getting the kinetic energy diagonal when I convert to the coordinates that diagonalize the potential energy. If you scroll all the way down you...
  44. A

    Solving for Normal Modes in a Non Similar Coupled Pendulum

    Homework Statement (The picture is having trouble being directed so I attached it) Hey guys, I'm trying to figure out the normal modes of a pendulum with two different masses. The lengths of the strings are the same and the weight of the strings are negligible. I can easily find everything...
  45. A

    Working on a blower which is directly coupled with motor

    Hi everyone, I am mechanical engineer by profession. I need little help from you guys. I am working on a blower which is directly coupled with motor. Now I am plannig to shift it to Belt Drive. Purpose behind doing this was that we need to save power and avoid alignment issues related to...
  46. D

    MHB Coupled ODEs from Euler Lagrange eq

    Given \(F = A(x)u_1^{'2} + B(x)u'_1u'_2 + C(x)u_2^{'2}\). \[ \frac{\partial F}{\partial u_i} - \frac{d}{dx}\left[\frac{\partial F}{\partial u_i'}\right] = 0 \] From the E-L equations, I found \begin{align*} \frac{d}{dx}\left[2Au_1' + Bu_2'\right] &= 0\\ \frac{d}{dx}\left[2Cu_2' + Bu_1'\right] &=...
  47. A

    Engineering The operation of magnetically coupled circuits

    Homework Statement A transformer has 600 primary turns and 150 secondary turns. The primary and the second resistances are 0.25Ω and 0.01 Ω respectively and the corresponding reactances are 1.0Ω and 0.04Ω respectively. Detemine the equivalent: 1. resistance 2. the reactance and 3. the...
  48. Astrum

    Solving QM-like Problem (Shankar, Coupled Mass)

    This is solving a coupled mass problem using the techniques used in QM, it's in the mathematical introduction of Shankar. This equation was obtained by using the solution for ##x(t) = x_i(0)cos(\omega _i t)## and plugging it into ##\left| x(t) \right \rangle = \left| I \right \rangle x_i...
  49. C

    Quick question on coupled pendulum kinetic energy

    I have found that the kinetic energy term for each mass on a coupled (by a spring) pendulum has no \dot{y} terms, as in the the masses do not move in the y direction at all. What am I missing here? I know they are connected, but in the first normal mode, both masses should move like regular...
  50. L

    Nonlinear coupled differential equation system - kinetics

    Dear All, Recently, I have measured a series of nonlinear vibrational spectra from which I would like to extract some useful information about kinetics of the exchange process occurring in the studied system. I need to fit my experimental data to kinetic model that is a solution of coupled...
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