State Definition and 1000 Threads

  1. R

    Ground state energy from the variational method

    Homework Statement Consider a one-dimentional particle in a box with infinite potential walls at x=0 and x=L. Employ the variational method with the trial wave function ΨT(x) = sin(ax+b) and variational parameters a,b>0 to estimate the ground state energy by minimising the expression E_{T}=...
  2. avito009

    How does the balanced chemical equation tell us the state?

    How does the balanced chemical equation tell us the products are in which state? Solid, Liquid, or Gas or aqueous?
  3. forkosh

    Is the wavefunction/quantum_state in electron interference experiments real?

    Several recent arxiv articles like http://arxiv.org/abs/1409.6290/ reviewing the pbr theorem http://arxiv.org/abs/1111.3328/ got me thinking about this again with respect to straightforward two-slit interference, which I'd thought simply and unambiguously resolved the issue in favor of "it's...
  4. D

    Solve Two Tasks with One DC Signal: Solid State Switch Circuit

    My goal is to use a single signal to do two things at the same time...when DC signal is applied turn transistor1 off and turn transistor2 on. Then when signal is not applied transistor1 returns to on and transistor2 returns to off. Frequency will be no more than 60Hz. What would this circuit...
  5. Xiaomin Chu

    What is the dimension of the state vector?

    Often ignored, but turned out to be a problem when trying to compute the commutator of position and spin. Pauli matrices clearly acting on two dimensional vectors while position on infinite dimensional vectors. But a system is described as a single state vector in Dirac notation. A system can of...
  6. Racer_Rob

    Steady state heat conduction into a very large solid

    Say you have a flat resistor that is producing heat. You place the resistor against a sheet of steel and wait for equilibrium. One side of the steel is now at the same temperature as the resistor (assuming negligible contact resistance), the other free-air side of the steel is at a lower...
  7. N

    Is this an acceptable way to state the EP?

    I'm helping write some supplementary notes for an undergraduate GR class at my university. I'm writing about the equivalence principle, do you find this way of stating matters acceptable? The equivalence principle as stated by Einstein asserts that in a sufficiently small vicinity of an event...
  8. K

    Fock State: A Picture from Physical Point of View

    I know there were some discussions in the forum about fock state. In text, fock state described as a state with fixed number of particle but unpredictable phase. Instead of talking about the math, could anyone show me a clear picture from physical point of view what is fock state? In the phase...
  9. D

    Why Is My MATLAB Steady State Error Different from Manual Calculation?

    I am trying to calculate the steady state error of the following system but unable to do it. I have used MATLAB and calculated the steady state error to be 0.1128 but don't understand the steps that I need to do to calculate this. Please help. Thanks
  10. Clear Mind

    Are these quantum states equivalent in Hilbert space representation?

    I've started few days ago to study quantum physics, and there's a thing which isn't clear to me. I know that a quantum state is represented by a ray in a Hilbert space (so that ##k \left| X \right\rangle## is the same state of ##\left| X \right\rangle##). Suppose now to have these three states...
  11. L

    Why isn't solution state a true physical state ?

    why isn't solution state a true physical state but a pseudo state?
  12. 9

    Kalman filter - help me to set up a state equation

    I would like to find the distance that a vehicle travels using a Kalman filter. The vehicle is a car that travels the road between two positions. The vehicle has a GPS/barometer/accelerometer device that collects position data, which I converted from a longitude and latitude to a North, East...
  13. bohm2

    Reality of the Quantum State: A Stronger Ψ-ontology Theorem

    Another theorem ruling out ψ-epistemic models: http://arxiv.org/pdf/1412.0669.pdf
  14. 9

    How Can a Kalman Filter Estimate Distance Using GPS and Velocity Data?

    I want to get the distance between points. I have a measurement of latitude, longitude and height from GPS/barometer systen (which I converted into north east down coordinates) and I have another measurement of the vehicle's velocity in the north east and down direction. To find the distance, I...
  15. S

    Probability and Energy of a Particle in Coherent State

    Homework Statement A particle in harmonic potential $$H=\hbar \omega (a^\dagger a+1/2)$$ is at ##t=0## in coherent state $$a|\psi>=2|\psi>$$ a) Calculate expected value of energy and it's uncertainty at ##t=0## b) With what probability do we at ##t=0## measure the energy less than ##3\hbar...
  16. fluidistic

    Sudden perturbation, particle in a box, ground state

    Hi guys! Suppose there's a particle in a box, initially in its ground state. Suppose that one chooses a system of coordinates such that the potential V(x) is 0 from 0 to L. Suppose that one suddenly perturbate the system at a particular time so that V(x) becomes 0 from 0 to 2L. I've calculated...
  17. E

    How can I represent this circuit in state space?

    I have this circuit and I must represent it in state space. I know the process because I have done similar ones but having trouble with this one. I have found the Kirchhoff equtations for the 2 loops and for the upper juction, whatever I do after I can't end up to two equations x'1 and x'2...
  18. J

    Normalization of ground state "1/2hw"

    Hello everyone: I didn't have a complete view of the quantum field theory and cannot understand this question. We now there will always be fluctuation field in the universe which corresponds to the ground state energy 1/2hw of harmonic oscillator. In the free space, we will use box...
  19. A

    Probability of finding particle in shifted ground state

    Homework Statement At t<0 a particle is in the ground state of the potential V(x)= \frac{1}{2} mw^2x^2 . At t=0 the potential is suddenly displaced by an amount x0 to V(x)= \frac{1}{2} mw^2(x-x_0)^2 . a) What is the probability of the particle being in the ground state; the first excited...
  20. gfd43tg

    Cooling of sphere with pseudo steady state condition

    Homework Statement A hot solid sphere of initial radius ##a## with a uniform initial temperature ##T_{0}## is allowed to cool under stagnant air at ambient temperature, ##T_{\infty}## . Assume the temperature within the sphere is uniform throughout the cooling process. Show that under...
  21. R

    Entropy of the initital state of the universe

    I saw an old interview with Roger Penrose where at one point he was talking about the degree of organization the universe exhibited at it's initial state. He said the second law of thermodynamics tells us as time passes the universe is becoming more disorderly, which means if we were to go back...
  22. C

    Is This State an Eigenstate of the 3D Harmonic Oscillator?

    Homework Statement For the three-dimensional harmonic oscillator H_{xyz} = \frac{p_x^2}{2m}+\frac{p_y^2}{2m}+\frac{p_z^2}{2m}+\frac{1}{2}m \omega^2 x^2 + \frac{1}{2}m\omega^2 z^2 + \frac{1}{2}m\omega^2 z^2 Consider: | \alpha_1 > = \frac{1}{\sqrt{2}} (|n_x = 0, n_y = 0, n_z = 0> + |n_x = 0...
  23. N

    The State of Energy to Matter Experimentation

    I have been researching energy to matter conversion experiments, and the only information that i have been able to find of a successful experiment is from 1997, when the University of Rochester was able to make a terawatt glass laser send photons into a stream of energized electrons from the...
  24. B

    Asking for assignement in solid state physics

    Hi, I would need a huge amount of assignments in solid state physics with solutions. I found assignement from other universities. Any book reference? Thank you
  25. G

    Extracting ground state in path integral

    Suppose you have the transition amplitude in the presence of a source <q''t''|q't'>_{f} To extract the ground state, we change the Hamiltonian to H-i\epsilon , because we can write: $$|q't'>=e^{iHt'} |n><n|q> \rightarrow e^{iE_0t'} |0><0|q>=<0|q>e^{iHt'} |0>=<0|q> |0 t'> $$ where only...
  26. C

    Write a state that will compute f=x/y^2 in maple

    Homework Statement Using maple cw version, trying to write a state that will compute f=x/y^2 over several iterations. y^2 is changing but x is dependent on a value input my user. I don't really know how to write the loop? I need the loop to run on an interval of different y values that I can...
  27. J

    Convective heat transfer and steady state conduction problem

    Hi all, I have a unique problem that I need help with A company's curing oven's exposed surface temperature is measured at 80°c when the surrounding air is 23°c. You think it should be insulated and wager to pay for the cost of this yourself if you can keep the savings incurred. Is this a smart...
  28. ZetaOfThree

    Solid State Physics problem book?

    What are some recommended resources with good problems (and preferably solutions as well) on Solid State Physics at the level of Kittel? I'm aware of Yung-Kuo Lim's "Problems and Solutions on Solid State Physics, Relativity and Miscellaneous Topics" which has graduate qualifying exam questions...
  29. G

    Engineering Analyzing DC Steady State in an RLC Circuit with a Closed and Opened Switch

    Homework Statement In the Figure Q1 (c), the switch S was closed for very long time before it is opened at time t = 0. Find the value of vC(t) and iL(t) at t = 0+ c L i.e. immediately after the switch was opened. Homework Equations V = IR The Attempt at a Solution From DC steady state, we...
  30. phoenixXL

    Why Is Aqueous Tension Treated Separately in Equilibrium Calculations?

    Question In a container of capacity 1-Litre, air and some liquid water is present in equilibrium at total pressure of 200 mm of Hg. This container is connected to another 1-Litre evacuated container. Find total pressure inside the container when equilibrium is again stabilized. Aqueous Tension...
  31. S

    What is the energy of the following state (quantum square)?

    Homework Statement [/B] What is the energy of an STM tunneling electron in the following state? This "quantum square" model can be seen as a "particle in a 2-D box" problem. <Refer to the picture below> The protrusions are Fe atoms and the surface is Cu(111). Given that the radius of an Fe atom...
  32. Z

    Transfer function of the state space model

    I have a state space model along with an observer and state feedback. I need to find the transfer function connecting the r (reference) to the y (output) I have this model on simulink. I know the A,B,C,D matrices. So, I can get the TF for the stateSpace with ss2tf function of matlab...
  33. P

    Solid State Theory Walter A. Harrison Solutions?

    Hi I was recently picked up solid state theory by Walter A. Harrison. I was wondering if anyone happened to have a solution set to this book as the publisher site does not have one up. Harrison has solution sets for other books up on the publisher's site so I feel like this one should be out...
  34. M

    Forming an Excimer - Explaining the Process for Xenon

    Hello, first post! Can anyone explain to me how an excimer is formed? Considering Xenon. I've gathered that an excited state Xe*, ground state Xe, and a 3rd body M react resulting in an Xe* excimer + M(carrying away excess energy). I'm struggling to find how the ground state Xe can have any...
  35. L

    Polarization state conventions

    Ok, so I keep reading about these concepts and every source says something different. Even within the same textbook, it says conflicting things. So you have a circularly polarized light that is coming TOWARDS you. That is considered left-circularly polarized or right-circularly polarized? I've...
  36. P

    State Space: time dependent states but time-independent output

    Let: $$x_1=A\sin{\omega t}$$ $$x_2=\dot{x}_1=A\omega \cos{\omega t}$$ $$y=A\omega$$ We want to represent this system in a state space model. The state transition matrix read: $$A=\begin{bmatrix} 0 & 1 &\\ -\omega^2 & 0 \\ \end{bmatrix}$$ I am not sure what the output matrix will be like. Can we...
  37. N

    Finding a State-Space Representation for Helicopter Pitch Angle Control

    I need help finding a state-space representation for the given system and locally linearizing it... Objective is to control the pitch angle theta, as an output, of the helicopter by regulating the rotor angle u, as an input. This is what I've done, but apparently it isn't correct, and I...
  38. J

    Most probable electron location in Hydrogen ground state

    From the ground state wave equation the most probable outcome of anyone measurement will be in the center of the atom, at the nucleus. The expectation value is found to be the Bohr radius. So does this mean that if you measure the position of an electron in a hydrogen atom in the ground state...
  39. Z

    How to Convert Mechanical System Equations to State Space Form?

    JL*QL'' + BL*QL' + k(QL - Qm) = 0 Jm*Qm'' + Bm*Qm' - k(QL - Qm) = u This is the equation set I have for a motor with a load. QL'' means second derivative and QL' means first derivative. I need to be able to obtain the state space representation of this model where X = [QL;QL';Qm;Qm'] (This is...
  40. Chestermiller

    News How Has the Michigan vs. Michigan State Rivalry Changed Over Time?

    History lesson from BIG BROTHER to little brother: What goes around comes around. :mad: MICHIGAN: GO BLUE Chet
  41. G

    Energy Resolution of a solid state X-Ray detector

    Homework Statement Hi all, I have been given the task of quantifying the energy resolution of a p-i-n semi-conductor x-ray detector and present it as a value in electron volts Homework Equations %Resolution=E FWHM / Ei Where E FWHM is the full width half maximum of a peak and Ei is the...
  42. Z

    Can You Implement Full State Feedback Without Direct State Observations?

    Below wikipedia page summarizes the full state feedback. Everything is clear but to be able to implement this controller I need to know my states. But What I know is just the A, B and C matrices. So, to be able to simulate this technique on simulink I need to observe the state, I think. Is this...
  43. M

    Conceptual Heat X-fer Question (Steady state, liquid changing temp as it flows)

    Homework Statement Not hw.. My teacher wants us to understand this as it is important for reactor design. A liquid is flowing through a tube of diameter D. The inner wall of the tube is maintained at a constant temperature of Ts. The liquid enters at a temperature of Tw1and leaves at a...
  44. B

    Analytical solution for bound state energies of infinite well

    Hi there I am trying to find bound state energies assuming infinite potential. I have been told it can be done by analytically solving Right Hand Side and Left Hand Side of an equation such as: E^1/2 tan(2ma^2E/4hbar)^1/2 = (V0-E)^1/2 If solved properly, it should give one curve (RHS), crossed...
  45. E

    MHB State the range of the reciprocal function?

    State the range of the reciprocal function of f(x) = - (x+3)^2 - 1. I'm not sure if I did this right. I wrote that y is above/equal to -1 and below/equal to 0. Is this correct? Also, how would you graph the reciprocal function of f(x) if there is no VA and only a HA?
  46. skate_nerd

    MHB Does this problem warrant a taylor expansion? (solid state physics)

    The whole problem I'm doing here is not even really relevant, so I won't go too much into it...I'm told to find an atomic form factor given some certain conditions, and I do a big gross integral and got this: $$f=(\frac{4}{4+(a_oG)^2})^2$$ where \(a_o\) is the Bohr radius and \(G\) is the...
  47. L

    Stable equilibrium state question

    If a system is in a stable equilibrium state,its energy is maximum for fixed value of entropy ,the parameters and the amounts of constituents.Im wondering why this is true?Homework EquationsThe Attempt at a Solution
  48. R

    Determine the state |n> given results and probabilities [QM]

    Homework Statement In a spin-\frac{1}{2} system all particles are in the state |\psi\rangle. 3 experiments performed and are separate, the results are as follows: Particle in state |\psi\rangle, measured S_z = \frac{\hbar}{2}, with P=1/4 Particle in state |\psi\rangle, measured S_x =...
  49. Erland

    Does the wave function really collapse into a state?

    Take the famous double slit (thought) experiment. The wave function for the photon is a superposition of two orthogonal states, one for each slit passage. But it is claimed to collapse into one of these two states when the photon hits the screen beyond, and then continue in this one state. But...
  50. J

    What state is Iron most magnetic?

    Hi guys, I'm designing and making a hydro powered generator for my college engineering project and I want to know what type of Iron e.g. Cast Iron or Wrought Iron has the highest magnetic field strength.
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