Sho Definition and 57 Threads

  1. K

    Advantages of a cone-shaped spring?

    I'm doing a personal experiment where I take a conical spring (that is, a spring with two different diameters on either end), hang it from the ceiling, and measure the period of oscillation for different masses hanging below the spring. I do this for two different orientations of the spring; one...
  2. W

    Analytic solution of the SHO for 1D Schrodinger

    At the point where we 'guess' a solution to this 2nd order ODE that cannot be done analytically, I was wondering why Griff and others choose $$e^{-x^2 / 2}$$ rather than just $$e^{-x^2}$$ I've plotted both here and am left wondering what's so different? If we guessed instead the unpopular...
  3. P

    Lorentz force on a charge due to a moving magnet

    Let's say I have a charge q which is viewed from its rest frame. So it's velocity v is 0. So the so-called magnetic component of its Lorentz force, which is q v x B, is 0. But I can have a magnet moving in this frame of reference. Let's say the velocity of this magnet according to the charge's...
  4. P

    Induced Magnetic Moment (vector) vs. Induced EMF (scalar)

    When I induce magnetic flux through a closed loop, I should expect the lines of flux produced by current in that loop to oppose the change of flux through that loop. But what happens when that loop, say a rectangular loop, is curved into the shape of the letter J (like a candy cane) and my flux...
  5. P

    Forces between a Solenoid and an External Permanent Magnet

    What happens if I have a permanent magnet outside an ideal solenoid? Does the permanent magnet rotate until the system reaches an energy minimum in its magnetic fields? Or does the permanent magnet fail to rotate because the magnetic field of the solenoid does not reach the magnet? Wouldn't...
  6. Chip

    An operator acting on the translated ground state of an SHO

    I am trying to perform the operation a on a translated Gaussian, ie. the ground state of the simple harmonic oscillator (for which the ground state eigenfunction is e^-((x/xNot)^2). First, I was able to confirm just fine that a acting on phi-ground(x) = 0. But when translating by xNot, so a...
  7. S

    Simple Harmonic Oscillator Zero Probability Points

    Hi, What is the physical meaning of zero probability of finding a particle in the square of the Quantum SHO wave function? the particle is supposed to oscillate about the equilibrium position, how would it go from an end point to the other end point without passing by certain points? Could the...
  8. Coffee_

    Is the Solution sin(t)H(t) for SHO a Particular Solution?

    So we have derived that for the differential equation: ##x(t)''+x(t)=\delta(t)## The solution is given by ##x=sin(t)H(t)## where ##H## is the Heaviside function. To find this we assumed that the system was in rest before ##t=0## and that position and velocity are continious. QUESTION: I am...
  9. Phynos

    Time taken for energy to drop 95% in damped SHO

    There is a post about the same problem here: https://www.physicsforums.com/threads/damped-oscilating-spring.12838/ It was helpful for solving part B. 1. Homework Statement A 10.6kg object oscillates at the end of a vertical spring that has a spring constant of 2.05x10^4 N/m. The effect of...
  10. G

    Temperature, Kinetic Energy, Boltzmann Factors, and SHO

    I am confused about the following; where am I going wrong here? 1. (1/2)kT is defined as the average kinetic energy of the molecules of a substance at temperature T, right? 2. You can derive the Boltzmann distribution/Boltzmann factors using (1/2)kT as the kinetic energy, making an argument...
  11. SalfordPhysics

    FORTRN90: Euler Midpoint Method for SHO

    Homework Statement Write a program to simulate motion of simple harmonic oscillator. Initial conditions: Let ω = 1, x(t=0) = 1, v(t=0) = 0. Integrate over 30 seconds in intervals of 0.05s. Homework Equations δ2x / δt2 = -ω2x As set of 2 coupled ODE's; x' = v, v' = -w2x The...
  12. S

    Spontaneous symmetry breaking in SHO

    Spontaneous symmetry breaking refers to the solution of a system loses some symmetry in its Lagrangian. Consider a Simple Harmonic Oscillator, its lagrangian is time translationally invariant but its solution is periodic in time, thus not time-translational invariant. Is this Spontaneous...
  13. R

    Missing h-bar in showing SHO in terms of ANHIL and CREA operators is correct

    this is the given: the problem is the middle term, if the h-bar w outside the set brackets is canceled with the h-bar w of the m/2hw, then there will be a h-bar w that is left introduced from the middle term, i.e. i\frac{w}{m}XP- i\frac{w}{m}PX = i\frac{w}{m}[X,P]= i\frac{w}{m}i\hbar but...
  14. C

    Green Function SHO - Reading Materials & Math Background

    hi, I need some reading materials on green function for SHO. my instructor provided a GF frequency and wanted us to find the deformation of poles , boundary conditions for the function. I need to know which mathematical background should I have to solve this. any useful material suggestion will...
  15. W

    Why we cannot solve quantum sho directly by fro envious series.

    I have just learned the quantum harmonic oscillator When we start to Solve the schodinger equation. y"= (K - x^2) y We look at large x behaviour and use a substitution y = u(x)* exp(-x^2 /2) to approximate the large x behaviour first, then we use series method to solve the equation...
  16. D

    Application of Schrodinger equation to SHO

    when Schrodinger equation is applied to SHO only positive value of potential energy changes it to Hermitian polynomial and hence solution is possible but potential energy is positive only when the particle is moving away from the the mean position.The sign of potential is negative when the...
  17. M

    How do ladder operators generate energy values in a SHO?

    Hello, I am currently studying ladder operator for a simple harmonic operator as a method for generating the energy values. This seem like a simple algebra question I am asking so I do apologize but I just can't figure it out. Here are my operator definitions...
  18. D

    Sign of potential energy of SHO

    Suppose the particle is at distance x from mean position and moving away . The standard formula for calculating potential U is U=-w here wis the work w=kxdx when the particle is moving away .On integration U=1/2Kx^2 . When the particle is moving towards mean position w=-kxdx on integration...
  19. H

    SHO ladder operators & some hamiltonian commutator relations

    Homework Statement For the SHO, find these commutators to their simplest form: [a_{-}, a_{-}a_{+}] [a_{+},a_{-}a_{+}] [x,H] [p,H] Homework Equations The Attempt at a Solution I though this would be an easy problem but I am stuck on the first two parts. Here's what I did at first...
  20. A

    Why Does Griffith's Derivation of the Quantum SHO Use This Method?

    In Griffith's derivation of the quantum SHO, he uses some funny math: first he considers asymptotic behavior to get ψ=Ae-(ε^2/2) then he 'peels off the exponential part' to say that ψ=h(ε)e-(ε^2/2) then he hopes that h(ε) will have simpler form than ψ(ε) I can kind of understand the first...
  21. S

    Heat Capacity of a classical ideal gas and SHO

    Homework Statement Ideal gas. In an ideal-gas model. N molecules move almost indepdently with very weak interactions between, in a three-dimensional box of volume V. Find the heat capacity of the system. SHO. Consider N independent SHOs in a system. each osciallating about a fixed point...
  22. K

    How Do Quantum Statistics Affect Energy Level Degeneracies in a SHO?

    Lets say we have two spin 0 particles that don't interact more than being indistingishable.. what are the degenercies for the energylevels? I would say: (n1, n2) D --------------------------------------- (0,0) 1...
  23. snoopies622

    Limit to SHO / EM field analogy

    For a simple harmonic oscillator, the creation and annihilation operators can be expressed as linear combinations of the position and momentum operators, \hat {a} = \sqrt { \frac {m \omega} {2 \hbar} } ( \hat {x} + \frac {i \hat {p} } { m \omega } ) \hat {a} ^{\dagger} = \sqrt...
  24. R

    SHO of Water Sloshing in a Container

    Homework Statement Consider a rectangular container, dimensions L x b, filled to level h with water. Water sloshes at low amplitude, y0 << h so that its surface remains always flat. Assuming the water has a density of δ, show that the potential energy is U(y) = \frac{1}{6} b δ g L y^2...
  25. S

    Derive Energy Values of Rigid Rotator & SHO Without Schrodinger Eq.

    is it possible to derive exact values of energies of rigid rotator and SHO without using Schrodinger equation ?Is it possible to derive energy values by using classical mechanics ?
  26. teroenza

    Time average of SHO kinetic energy = (1/2)E

    Homework Statement I believe I understand the problem except I cannot get the time average of [sin(wt-d)]^2 = ½ I can do the rest once this is established. Homework Equations Average of a function= <function>= 1/(period)* integral(f*dt) from 0 to the period Function to be...
  27. D

    How does adding mass to a spring system affect its amplitude?

    Homework Statement You have a horizontal spring system such that it undergoes SHO on a frictionless surface. with a known mass attached at the end of the spring. When that mass reaches its maximum position (amplitude) a second identical mass is dropped on top of the initial, effectively...
  28. A

    SHO Ladder Method missed states?

    Following Griffiths derivation on pg 44 of the eigen-states of SHO Hamiltonian, he says that we can now find all eigenvalues, but doesn't say how he knows that a and a dagger will indeed take you between nearest neighboring orthogonal states. in other words, how do we know the ladder...
  29. N

    Solving for Constants in Perturbed Simple Harmonic Oscillator with HF Potential

    Homework Statement The potential of a simple harmonic oscillator of HF has the following form \frac{1}{2}kx^2 + bx^3 + cx^4 The first part of the problem involved finding expressions for the first-order energy corrections for the first three states, which I found below. Basically the x3 term...
  30. O

    Basic Quantum mechanics, H2 approximation with SHO

    Homework Statement A H2 molecule can be approximated by a simple harmonic oscillator having spring constant k = 1.1*10^3 N/m. Find a() the energy levels, and (b) the possible wavelengths of photons emitted when the H2 molecule decays from the third excited state eventually to the ground...
  31. J

    SHO: Find amplitude given k, and x,v,a at unknown time

    Homework Statement A block attached to a spring is experiencing simple harmonic motion. You know the value of postion, velocity, and acceleration at an unknown time. Find the period of oscillation, the mass of the block, and the amplitude of oscillation. We were given values for k, x, v, a...
  32. B

    Oscillating mass in a liquid, SHO

    Homework Statement A body of uniform cross-sectional area A and mass density \rho floats in a liquid of density \rho_0 (where \rho < \rho_0), and at equilibrium displaces a volume V. Making use of Archimedes principle (that the buoyancy force actign on a partially submerged body is equal to...
  33. N

    SHO in 2D - ground state energy

    Homework Statement A two-dimensional harmonic oscillator is described by a potential of the form V(x,y) = 1/2 m \omega^{2}(x^{2}+y^{2} + \alpha (x-y)^{2} where \alpha is a positive constant. Homework Equations Find the ground-state energy of the oscillatorThe Attempt at a Solution I have tried...
  34. J

    Everage energy of a gas of quantom SHO

    Homework Statement [/U] The average energy of a gas of quantum SHO is Eav= \sum_{n=0}^{\infty}n\hbar\omega e^(-n\hbar\omega/kT)\div \sum_{n=0}^{\infty}e^(-n\hbar\omega/kT) can be solved to be Eav=\hbar\omega\div \left \{ e^\left ( \hbar\omega/kt \right ) \right \}-1 make use of the following...
  35. LarryS

    Quantum SHO Wave Functions not Complex?

    The Hermite Polynomials are solutions to the Schrödinger equation for the Quantum Simple Harmonic Oscillator. But the Hermite Polynomials are real, not complex. I thought that solutions to the Schrödinger equation always had to be complex. What am I not understanding? Thanks in advance.
  36. LarryS

    What are null oscillations in quantum systems?

    What does the Ground State of a quantum simple harmonic oscillator represent physically? Thanks in advance.
  37. B

    2 non-interacting fermions in 1D SHO

    Homework Statement Two identical non-interacting spin 1/2 particles are in the one-dimensional simple harmonic oscillator potential V(x) = kx2/2. The particles are in the lowest-energy triplet state. a. Write down the normalized space part of the wave function. b. Calculate the energy of...
  38. B

    1D SHO in external electric field

    Homework Statement I have a charged particle in a 1D harmonic oscillator, on which an externally applied electric field acts, such that the Hamiltonian can be written: \frac{p^2}{2m}+\frac{kx^2}{2}-qEx The problem asks to first find the first (trivial) and second order corrections to...
  39. I

    Quantum:- SHO potential and its energy

    Homework Statement the energy levels of a particle mass in a symmetric 3d SHO potential are: E = (nx + ny + nz + 3/2)*h-bar*\sqrt{\frac{C}{m}} C=constant n=principal quantum number = nx + ny + nz A) If 10 electrons are in the potential what's the lowest possible value for the total energy...
  40. C

    Compute SHO Propagator: Eigenfunction Expansion

    I know how to do SHO propagator by computing the action. I was only trying to do it via the eigenfunction expansion K(x’,x;t)=sum_ i phi_i(x’) phi_i(x) exp(-iε_it/hbar )=(m omega/pi*hbar) sum_i=-^infty h_i(y’) h_i(y) exp[-(y**2+y’**2)/2] [s(t)/2]**i with s(t)=exp(-iomega t) This...
  41. M

    Quantum - Projection Probability - Projection amplitudes for SHO states.

    Quantum - Projection Probability - "Projection amplitudes for SHO states." Given the two normalized 2D SHO wave functions <x,y|mx[/SUB ],ny> for the second energy level n = nx + ny = 1 in the m[SUB]x[/SUB ],n[SUB]y representation: <x,y|1,0> = (2/pi)1/2xexp[-(x2+y2)/2] <x,y|0,1> =...
  42. L

    How Does Initial Velocity Affect SHM Equation for a Mass-Spring System?

    Homework Statement A horizontal massless spring of spring constant k is attached to a immovable wall at one end and a mass of 0.45kg at the other end. The spring which was not originally under tension, is now extended by 0.18 m by pulling the mass horizontally. The mass was then released by...
  43. Pengwuino

    Squeeze state in quantum SHO, uncertainty

    SOLVED: Squeeze state in quantum SHO, uncertainty Homework Statement So we're working with what are called squeeze states defined as |nu> = S(nu)|0> where nu is a real number, |0> the ground state of the oscillator, and S(nu) = exp[nu(a^2 - a*^2)/2] with a* = hermitian conjugate of a...
  44. N

    Constant force perturbation of the quantum SHO

    [SOLVED] Constant force perturbation of the quantum SHO Homework Statement We're supposed to consider the Hamiltonian for the simple harmonic oscillator: \hat{H}_{0} = \hat{p}^{2}/2m + m\omega^2\hat{x}^2/2 With a perturbation, so that \hat{H} = \hat{H}_0 + \hat{H}' , where \hat{H}' =...
  45. E

    What Physical Situation is Governed by the Standard SHO Potential?

    Homework Statement My QM book says that the standard SHO potential is m \omega^2 x^2/2 . Can someone give me an example of a physical situation that is governed by this potential. It seems rather out of nowhere to me... Homework Equations The Attempt at a Solution
  46. I

    SHO Eigenvalues with Non-Standard Potential

    We know the eigenvalue relation for the Hamiltonian of a SHO (in QM) though relating the raising and lowering operators we get: H= \hbar \omega (N+1/2) This is true for H=\frac{p^2}{2m}+\frac{m \omega^2 x^2}{2} I would like to solve for another case where V=a\frac{m \omega^2 x^2}{2} where...
  47. B

    Quantum SHO Ladder Operator in Mathcad

    A Quantum I problem set asks me to graph the first 15 states of the simple harmonic oscillator. Our department uses mathcad heavily, so I think I should write a function that applies the ladder operator repeatedly to generate the wave function. I'm having trouble getting it to actually return a...
  48. E

    What Is the Significance of 'n' in the Solutions of the Quantum SHO?

    The even solutions of an SHO are: h^+(y) = \sum_{s = 0}^{\infty}a_s y^{2s} where a is given by the recursion a_{s+1} = a_s \left( \frac{4s + 1 - \epsilon}{2(s+1)(2s+1)} \right) The solutions are square integrable iff a_n = 0 so that the polynomial is finite. What I do not...
  49. M

    What are the allowed energies for a quantum harmonic oscillator?

    Hi all I was just looking through my notes from my first year of my degree, and I couldn't find a missing bit. I know that Planck's postulate states that the allowed energies of a quantum simple harmonic oscillator are 0, hf, 2hf etc and that by the Schroedinger equation, you get E(n)=(n+1/2)...
  50. C

    SHO on a Conveyor Belt: Exploring the Dynamics of a Mass on a Moving Surface

    This one is killing me. Homework Statement A SHO is resting on a horizontal surface with which it has static and kinetic friction coefficients us and uk . We have k for the spring constant and m for the mass. The surface is actually part of a conveyor belt that is maintained at a speed u...
Back
Top