Harmonic Definition and 1000 Threads

  1. C

    Quantum Harmonic Oscillator problem

    Homework Statement For the n = 1 harmonic oscillator wave function, find the probability p that, in an experiment which measures position, the particle will be found within a distance d = (mk)-1/4√ħ/2 of the origin. (Hint: Assume that the value of the integral α = ∫0^1/2 x^2e^(-x2/2) dx is...
  2. N

    Exploring Simple Harmonic Motion: A=14cm, ω=3.0Hz

    Homework Statement Write a simple harmonic motion with amplitude 14cm , frequency 3.0Hz , and maximum displacement at t=0.The Attempt at a Solutiony (t) = A cos (ωt) = 14 cos (2πt/T) Dealing with angular frequency is easy. But deal with natural frequency throws me off course.
  3. F

    Harmonic Oscillators: Resonance Bandwidth & Frequency Range

    Show that the resonance bandwidth corresponds to the frequency range for which –1 < tan χ < +1. (The resonance bandwidth is the range for which the average power is greater than 0.5 times the peak power.) I'm pretty damn stumped with this.
  4. V

    Derivative of Spherical Harmonic for negative m

    Hello! Homework Statement I want to evaluate the derivative of spherical harmonics with respect to the azimuthal angle and express it in terms of spherical harmonics.2. Homework Equations and 3. The Attempt at a Solution I have calculated the derivative of the spherical harmonic with respect...
  5. W

    What Differentiates Simple Harmonic Motion from ψ = Amod(t) cos (wavt)?

    1. What is the difference between ψ = Amod(t) cos (wavt)and the simple harmonic oscillator? 3. A. The amplitude is time dependent B. The amplitude,Amod , is twice the amplitude of the simple harmonic oscillator, A. C. The oscillatory behavior is a function of ? instead of the period, T...
  6. W

    Harmonic Oscillator: Impulse needed to counteract energy loss

    Homework Statement The pendulum of a grandfather clock activates an escapement mechanism every time it passes through the vertical. The escapement is under tension (provided by a hanging weight) and gives the pendulum a small impulse a distance l from the pivot. The energy transferred by...
  7. KodRoute

    Equations of the harmonic oscillator

    Hello, my book explains detailed the proofs of these three formulas: y = Asin(ωt + φo) v = ωAcos(ωt + φo) a = -ω²Asin(ωt + φo) Where a is acceleration, v is velocity, ω is angular velocity, A is amplitude. The book uses the following figures: Figure a) -->...
  8. P

    Simple Harmonic Motion amplitude problem

    Homework Statement An object is undergoing simple harmonic motion with frequency f = 3.1 Hz and an amplitude of 0.15 m. At t = 0.00 s the object is at x = 0.00 m. How long does it take the object to go from x = 0.00 m to x = 7.00×10-2 m. Homework Equations x(t)=Asin(ωt) The Attempt...
  9. E

    Nonlinear optics: second harmonic generation

    Hello, I'm studying basic nonlinear optics and I would like to solve a couple doubts about (basic) photon interaction. Let a monocromatic (of frequency ω) electromagnetic field propagate through a nonlinear medium and let the third(and higher)-order terms in the relation between the...
  10. C

    Harmonic oscillator Hamiltonian.

    I know I've seen this point about roots discussed somewhere but I can't for the life of me remember where. I'm hoping someone can point me the right direction. Here's the situation:- The standard derivation of the quantum HO starts with the classic Hamiltonian in the form H = p2 + q2...
  11. C

    Why Do Harmonic Motion Equations Differ Across Sources?

    I was hoping that someone could explain why these different equations can be found from different sources please. The time dependent position, x(t), of an underdamped harmonic oscillator is given by: x(t)=e^{-\gamma t}acos(\omega_{1}t-\alpha) where \gamma is the damping coefficient, and...
  12. D

    Simplifying entropy for a harmonic oscillator in the limit of large N

    Homework Statement Hey guys, So I have this equation for the entropy of a classical harmonic oscillator: \frac{S}{k}=N[\frac{Tf'(T)}{f(T)}-\log z]-\log (1-zf(T)) where z=e^{\frac{\mu}{kT}} is the fugacity, and f(T)=\frac{kT}{\hbar \omega}. I have to show that, "in the limit of...
  13. M

    How Can I Solve This Compound Harmonic Motion Problem with Different Methods?

    Homework Statement Determine the motion of this mechanical system satisfying the initial conditions :- y1(0) = 1 y2(0) = 2 y1'(0) = -2*sqrt(6) y2'(0) = sqrt(6) Hint : there are 4 different methods you can use to solve this problem. They all give the same exact result. I need to...
  14. U

    Solving the Shroedinger equation for a harmonic oscillator potential

    Hello, I have been studying Introduction to Quantum Mechanics by Griffith and in a section he solves the Schrodinger equation for a harmonic oscillator potential using the power series method. First he rewrites the shroedinger equation in the form d^2ψ/dε^2 = (ε^2 - K)ψ , where ε=...
  15. M

    Hamiltonian For The Simple Harmonic Oscillator

    I am reading an article on the "energy surface" of a Hamiltonian. For a simple harmonic oscillator, I am assuming this "energy surface" has one (1) degree of freedom. For this case, the article states that the "dimensionality of phase space" = 2N = 2 and "dimensionality of the energy surface" =...
  16. Runei

    Solution: Solving Harmonic Oscillation Differential Equation

    Hello, When I have the differential equation \frac{dY(x)}{dx} = -k^2 Y(x) The solution is of course harmonic oscillation, however, looking at various places I see the solution given as: Y(x) = A cos(kx) + B sin(kx) instead of Y(x) = A cos(kx + \phi_1) + B sin(kx + \phi_2) Isnt...
  17. D

    Speed of a wave on a string and Frequency of 3rd Harmonic

    Homework Statement Tension = 400 N Mass = 4g Length = .96m What is the speed of the wave on a string? What is the frequency of the 3rd harmonic? Homework Equations v=√T/(m/L) v=fλ The Attempt at a Solution v=√400N/(.004kg/.96m) = 310m/s...am I correct? f=v/λ...
  18. P

    Simple Harmonic Motion: Simple Pendulum

    If we apply the small angle approximation so that a simple pendulum can be considered to be under going SHM, what kind of potential energy would the pendulum bob be having? If the answer is gravitational potential energy, then we have a contradiction because this would mean that the bob would...
  19. 6c 6f 76 65

    Harmonic oscillation; new amplitude?

    Homework Statement A block with a mass M is located on a frictionless, horizontal surface and is attached to a horizontal spring with spring stiffness k. The block is being pulled out to the right a distance x=x_0 of equilibrium and released at t = 0. At time t_1, corresponding to \omega...
  20. P

    Simple Harmonic Motion - Potential energy

    For a mass on a spring (vertical set up) why is potential energy U defined as 1/2 kx^2? This is just the elastic potential energy. Shouldn't it be U = 1/2 kx^2 + mgh? Both the elastic AND potential energy? Also, for a simple pendulum at a very low amplitude, the potential energy is all...
  21. P

    Simple Harmonic Motion - Mass on a Spring

    For a mass on a spring (vertical set up) undergoing SHM, we equate the restoring force, -kx, to -ω^2 x, coming to a conclusion that ω = \sqrt{\frac{k}{m}}. My question is, is the restoring force |mg - T| Where T is the tension in the spring? Because this seems to be the net force. I am used to...
  22. KiNGGeexD

    Why Do Simple Harmonic Motion Equations Differ?

    Simple harmonic motion (Again) :( This is not a question about a problem it is more about the position of a simple harmonic oscillator as a function of time:) I went through it in a lecture yesterday and found using the energy in simple harmonic motion to bex(t)= A cos(ωt +φ) Which is fine...
  23. KiNGGeexD

    Simple Harmonic Motion (Total Energy)

    I have a question about the derivation that I have attached! I understand that both KE and U are 1/2 kA^2 So how is it that the two combine is also equal to 1/2kA^2Not sure if I'm missing something but I'm a little confused :(
  24. A

    Quantum Harmonic Oscillator

    A harmonic oscillator with frequency ω is in its ground state when the stiffness of the spring is instantaneously reduced by a factor f2<1, so its natural frequency becomes f2ω. What is the probability that the oscillator is subsequently found to have energy 1.5(hbar)f2ω? Thanks
  25. F

    One-dimensional linear harmonic oscillator perturbation

    Homework Statement Consider a one-dimensional linear harmonic oscillator perturbed by a Gaussian perturbation H' = λe-ax2. Calculate the first-order correction to the groundstate energy and to the energy of the first excited state Homework Equations ψn(x) = \frac{α}{√π*2n*n!}1/2 *...
  26. R

    Interesting harmonic motion lab

    Homework Statement This is a required analysis for my Physics II lab. We recorded the motion of an object oscillating on spring, and are asked to use the slopes of different graphs that we plotted using the data collected in lab in order to find the spring constant (k). Both graphs were...
  27. E

    Optical thickness of the second harmonic cyclotron motion in a plasma

    Homework Statement Let's consider a Tokamak with major radius R=1m and minor radius a=0.3m, magnetic field B=5T with a deuterium plasma with central density 10^{20}m^{-3}, central temperature 1keV and parabolic temperature and density profiles \propto (1-r^2/a^2) a) Find the electronic...
  28. L

    Simple Harmonic Motion vibrations

    Homework Statement Find the period of low-amplitude vertical vibrations of the system shown. The mass of the block is m. The pulley hangs from the ceiling on a spring with a force constant k. The block hangs from an ideal string...
  29. U

    Ground state of harmonic oscillator

    Shouldn't the integrating factor be ##exp(\frac{m\omega x}{\hbar})##? \frac{\partial <x|0>}{\partial x} + \frac{m\omega x}{\hbar} <x|0> = 0 This is in the form: \frac{\partial y}{\partial x} + P_{(x)} y = Q_{(x)} Where I.F. is ##exp (\int (P_{(x)} dx)##
  30. S

    Find wavefunction of harmonic oscillator

    Homework Statement We want to prepare a particle in state ##\psi ## under following conditions: 1. Let energy be ##E=\frac{5}{4}\hbar \omega ## 2. Probability, that we will measure energy greater than ##2\hbar \omega## is ##0## 3. ##<x>=0## Homework Equations The Attempt at a...
  31. O

    Simple Harmonic Motion, memory device

    What is a good way to memorize that ## \omega = \sqrt{\dfrac{k}{m}} ## ? I always confuse it with: ## T = 2\pi \sqrt{\dfrac{m}{k}}## , and can never tell them apart. (i guess part of it is that I'm not too familiar with it yet)
  32. S

    Harmonic oscillator in electric field

    Homework Statement Potential energy of electron in harmonic potential can be described as ##V(x)=\frac{m\omega _0^2x^2}{2}-eEx##, where E is electric field that has no gradient. What are the energies of eigenstates of an electron in potential ##V(x)##? Also calculate ##<ex>##. HINT: Use...
  33. S

    One dimensional harmonic oscillator

    Homework Statement One dimensional harmonic oscillator is at the beginning in state with wavefunction ##\psi (x,0)=Aexp(-\frac{(x-x_0)^2}{2a^2})exp(\frac{ip_0x}{\hbar })##. What is the expected value of full energy? Homework Equations ##<E>=<\psi ^{*}|H|\psi >=\sum \left | C_n \right |^2E_n##...
  34. MarkFL

    MHB Ernesto's Question: Proving Harmonic & Arithmetic Progressions

    Here is the question: I have posted a link there to this thread so the OP can view my work.
  35. H

    Simple Harmonic Motion: Giancoli Problem Help

    Homework Statement A 1.15-kg mass oscillates according to the equation x = .650cos(8.40t) where x is in meters and t in seconds. Determine a)the amplitude, b)the frequency, c) the total energy of the system, and d) the kinetic and potential energy when x = 0.360m. Homework Equations x...
  36. Nemo's

    Show that the motion is simple harmonic

    Homework Statement A solid wooden cylinder of radius r and mass M. It's weighted at one end so that it floats upright in calm seawater, having density ρ the buoy is pulled down a distance x from it's equilibrium position and released. a- Show that the block will undergo s.h.m b- Determine...
  37. D

    Frame of reference in a simple harmonic motion vertical spring

    I have doubts of how can I put my frame of reference in a simple harmonic motion vertical spring. Normally the books choose the origin in the equilibrium position and the positive distance (x>0) downward, and in this conditions Newton´s second law is: ma=-kx; but instead of putting the positive...
  38. K

    The Importance of Damping in Simple Harmonic Motion Explained

    I need help for the second part please. How do the oscillations being damped prevent them from being S.H.M. as well the other 2 points? I need an explanation so I can understand. The oscillations would still have the same time period eve if they are damped. Low frequency due to...
  39. T

    Simple Harmonic Motion: Amplitude of Oscillation for a Spring System

    Homework Statement The masses in figure slide on a frictionless table.m1 ,but not m2 ,is fastened to the spring.If now m1 and m2 are pushed to the left,so that the spring is compressed a distance d,what will be the amplitude of the oscillation of m1 after the spring system is released...
  40. C

    Pendulum with Spring: Finding Position and Period

    Homework Statement A system consists of a spring with force constant k = 1250 N/m, length L = 1.50m, and an object of mass m = 5.00kg attached to the end. The object is placed at the level of the point of attachment with the spring unstretched, at position yi= L, an then is released so that it...
  41. W

    Solve 1D Harmonic Oscillator: Expectation Value of X is Zero

    Homework Statement I need to show that for an eigen state of 1D harmonic oscillator the expectation values of the position X is Zero. Homework Equations Using a+=\frac{1}{\sqrt{2mhw}}(\hat{Px}+iwm\hat{x}) a-=\frac{1}{\sqrt{2mhw}}(\hat{Px}-iwm\hat{x}) The Attempt at a Solution...
  42. L

    Harmonic motion and acceleration

    A system exhibits simple harmonic motion with a frequency of 0.85 cycles per second. Calculate the acceleration experienced by the mass 3.0 m from the equilibrium This question seems simple, I haven't really tried anything cause I can't figure out how to start. I need help to start this...
  43. D

    Harmonic osilator energy using derivatives

    Homework Statement Show that the energy of a simple harmonic oscillator in the n = 2 state is 5Planck constantω/2 by substituting the wave function ψ2 = A(2αx2- 1)e-αx2/2 directly into the Schroedinger equation, as broken down in the following steps. First, calculate dψ2/dx, using A for A, x...
  44. S

    How do I find the frequency of oscillation for a damped harmonic oscillator?

    Homework Statement The terminal speed of a freely falling object is v_t (assume a linear form of air resistance). When the object is suspended by a spring, the spring stretches by an amount a. Find the formula of the frequency of oscillation in terms of g, v_t, and a. Homework Equations the...
  45. A

    Distance Traveled by Harmonic Oscillator in 1 Period

    Homework Statement A harmonic oscillator oscillates with an amplitude A. In one period of oscillation, what is the distance traveled by the oscillator? Homework Equations I'm not sure which equation applies if any? The Attempt at a Solution My guess was 2A but the answer was 4A...
  46. L

    Queries on Damped Harmonic Motion

    So we know that SHM can be described as: x(t) = Acos(ωt + ϕ) v(t) = -Aω sin(ωt + ϕ) a(t) = -Aω^2 cos(ωt + ϕ) it can be easily said that the max acceleration (in terms of magnitude) a SHM system can achieve is Aω^2 In Damped Harmonic Motion we know that: x(t) = (A)(e^(-bt/2m))cos(ωt + ϕ) given...
  47. G

    How Do Quantum Harmonic Oscillator Ladder Operators Affect State Vectors?

    Homework Statement Given a quantum harmonic oscillator, calculate the following values: \left \langle n \right | a \left | n \right \rangle, \left \langle n \right | a^\dagger \left | n \right \rangle, \left \langle n \right | X \left | n \right \rangle, \left \langle n \right | P \left | n...
  48. D

    Simple harmonic motion of two solid cylinders attached to a spring

    Homework Statement ) Two uniform, solid cylinders of radius R and total mass M are connected along their common axis by a short, massless rod. They are attached to a spring with force constant k using a frictionless ring around the axle. If the spring is pulled out and released, the cylinders...
  49. skate_nerd

    Potential well, harmonic oscillator

    Homework Statement Parabolic harmonic oscillator potential well. A particle is trapped in the well, oscillating classically back and forth between x=b and x=-b. The potential jumps from Vo to zero at x=a and x=-a. The particle's energy is Vo/2. I need to find the potential function V(x) in...
  50. D

    An attempt frequency for a harmonic oscillator?

    An "attempt frequency" for a harmonic oscillator? Homework Statement What is the "attempt frequency" for a harmonic oscillator with bound potential as the particle goes from x = -c to x = +c? What is the rate of its movement from -c to +c? Homework Equations v...
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