Simple harmonic oscillator Definition and 109 Threads

  1. Q

    Ground State of the Simple Harmonic Oscillator in p-space

    Homework Statement A particle is in the ground state of a simple harmonic oscillator, potential → V(x)=\frac{1}{2}mω^{2}x^{2} Imagine that you are in the ground state |0⟩ of the 1DSHO, and you operate on it with the momentum operator p, in terms of the a and a† operators. What is the...
  2. AdrianHudson

    Frequency of a simple harmonic oscillator

    Homework Statement Consider a mass hanging from an ideal spring. Assume the mass is equal to 1 kg and the spring constant is 10 N/m. What is the characteristic frequency of this simple harmonic oscillator? Homework Equations No idea I think Hookes law F=-ky Some other relevant...
  3. L

    Simple Harmonic Oscillator Equation Solutions

    These are practice problems, not homework. Just wanting to check to see if my process and solutions are correct. 1. Given the following functions as solutions to a harmonic oscillator equation, find the frequency f correct to two significant figures: f(x) = e-3it f(x) = e-\frac{\pi}{2}it 2...
  4. O

    Sakurai page 91: Simple Harmonic Oscillator, trouble understanding

    From page 91 of "Modern Quantum Mechanics, revised edition", by J. J. Sakurai. Some operators used below are, a = \sqrt{\frac{m \omega}{2 \hbar}} \left(x + \frac{ip}{m \omega} \right)\\ a^{\dagger} = \sqrt{\frac{m \omega}{2 \hbar}} \left(x - \frac{ip}{m \omega} \right)\\ N = a^{\dagger}...
  5. S

    Determining exact solutions to a perturbed simple harmonic oscillator

    Homework Statement Consider as an unperturbed system H0 a simple harmonic oscillator with mass m, spring constant k and natural frequency w = sqrt(k/m), and a perturbation H1 = k′x = k′sqrt(hbar/2m)(a+ + a−) Determine the exact ground state energy and wave function of the perturbed system...
  6. H

    Simple Harmonic Oscillator Problem

    Homework Statement The position of a mass that is oscillating on a Slinky (which acts as a simple harmonic oscillator) is given by 18.5 cm cos[ 18.0 s-1t]. What is the speed of the mass when t = 0.360 s? Homework Equations x(t)=Acos(ωt+θ) v(t)=-Aωsin(ωt+θ) The Attempt at a Solution...
  7. S

    Simple Harmonic Oscillator: Kinetic and Potential Energy Equilibrium

    Homework Statement A simple harmonic oscillator has an amplitude of 0.1 m. At what displacement will its kinetic and potential energies be equal? Homework Equations The Attempt at a Solution I'm trying to figure out how to solve this problem but I'm totally stuck and even don't...
  8. P

    Solving the Simple Harmonic Oscillator Equation of Motion: Tips and Tricks

    Homework Statement A physical system is designed having the following equation of motion md2x/dt2 + c(dx/dt) - kx = 0. (a) From the corresponding subsidiary equation, find the solution to this equation of motion. (HINT: use the solution of the damped harmonic oscillator as a guide)...
  9. Hepth

    Thought Prob : Regenerative Damping of a Simple Harmonic Oscillator

    So I was just thinking about regenerative braking, piezoelectric sensors/strain gauges, magnetic-induced currents etc. and I thought of a question that would make a simple/decent discussion/practice in general engineer/physics (lots of /'s) Suppose you have a simple harmonic oscillator :: WALL...
  10. Y

    Underdamped Oscillator Solution: Deriving x(0) and v(0)

    Homework Statement Show that the underdamped oscillator solution can be expressed as x(t)=x_{0}e^{-γt}[cos(Ω't+((v_{o}+γx_{o})/(x_{o}Ω')sinΩ't] and demonstrate by direct calculation that x(0)=x_{o} and \dot{x}(0)=v_{o} Homework Equations The underdamped oscillator solution is...
  11. P

    Understanding Free Modes in Simple Harmonic Oscillators

    In the context of normal modes, what is a free mode? When the whole system is in motion?
  12. J

    Classical Mechanics: Simple harmonic oscillator problem

    Homework Statement A simple harmonic oscillator with mass m = 1/2 and k = 2 is initially at the point x = √3 when it is projected towards the origin with speed 2. Find the equation of motion describing x(t). Homework Equations x=Asin(ωt+θ) The Attempt at a Solution At t=0...
  13. D

    Fortran Fortran Simple Harmonic Oscillator Problem

    Hello fellow computer physics nerds, I'm trying to write a program to plot the positions of the three particles connected by two springs (one dimensional) in Fortran 90. I have a main program block and a module that calls a PGPLOT. My problem is that the positions of the second and third...
  14. G

    Find the expectation value of momentum squared for a simple harmonic oscillator

    Find the expectation value of (px)2, keeping in mind that ψ0(x) = A0e−ax2 where A0 = (2mω0/h)^1/4, and <x2> = ∫x2|ψ|2dx = h_bar / 2mω0 <ψ(x)|px2|ψ(x)> = ∫ψ(x)(pop2)ψ(x) dx pop = [hbar / i] (\delta/\deltax) I'm not going to attempt to type out me solving the integral because it...
  15. V

    Quantum Mechanics, Simple harmonic oscillator, partition function

    Homework Statement Compute the partition function Z = Tr(Exp(-βH)) and then the average number of particles in a quantum state <nα > for an assembly of identical simple harmonic oscillators. The Hamiltonian is: H = \sum _{k}[(nk+1/2)\hbar - \mu nk] with nk=ak+ak. Do the calculations once...
  16. S

    Period of a simple harmonic oscillator

    Hi I'm having problems with solving this question: a 90.0 kg skydiver hanging from a parachute bounces up and down with a period of 1.50 seconds. What is the new period of oscillation when a second skydiver, whose mass is 60.0 kg, hangs from the legs first? the answer is 1.94 seconds...
  17. J

    Quantum Simple Harmonic Oscillator

    Homework Statement The period of a macroscopic pendulum made with a mass of 10 g suspended from a massless cord 50 cm long is 1.42 s. (a) Compute the ground state (zero-point) energy. (b) If the pendulum is set into motion so that the mass raises 0.1 mm above its equilibrium position, what will...
  18. M

    Why Must the State of a Quantum SHM Particle Be of This Form?

    Homework Statement We know that a particle in SHM is in a state such that measurements of the energy will yield either E_0 or E_1 (and nothing else), each with equal probability. Show that the state must be of the form \psi = \frac{1}{\sqrt2} \psi_0 + \frac{e^{i \phi}}{\sqrt2} \psi_1 where...
  19. P

    Proving solution for Schrodinger's Simple Harmonic Oscillator

    Homework Statement Hi guys. I've been working on this problem for a while, it's starting to frustrate me. "Show that the function of Ѱ=e^(-bx^2) with b=mw/2ħ is a solution and that the corresponding energy is ħw/2." Homework Equations Schrodinger Eqn...
  20. Y

    Who can solve the probability of perturbation in simple harmonic oscillator

    Pleae help me. a),b),c) was already solved. but question d) is not.
  21. R

    Simple harmonic oscillator - scaled variables

    The TISE can be written as -\frac{\hbar^{2}}{2m}\frac{d^{2}u}{dx^{2}} + \frac{1}{2}m\omega_{0}^{2}x^{2}u = Eu Now my lecture notes say that it is convenient to define scaled variables y = \sqrt{\frac{m\omega_{0}}{\hbar} x} and \alpha = \frac{2E}{\hbar\omega_{0}} Hence \frac{d}{dx} =...
  22. B

    Probability of a particle in a simple harmonic oscillator -

    Homework Statement What is the probability that a particle in the ground state of a simple harmonic oscillator 1-D potential will be found outside the region accessible classically Homework Equations ∫(between 1 and infinity) e^(-y^2 ) dy=0.08π^(1/2) I feel like it's quite a...
  23. K

    Simple Harmonic Oscillator Problem with Slight Variation

    Homework Statement A particle is moving in a simple harmonic oscillator potential V(x)=1/2*K*x^2 for x\geq0, but with an infinite potential barrier at x=0 (the paddle ball potential). Calculate the allowed wave functions and corresponding energies.Homework Equations I am thinking that the...
  24. M

    Under what conditions is a pendulum a Simple Harmonic Oscillator, why?

    For part of my lab write up on pendulum motion, my professor wanted us to find out why a pendulum was not a simple harmonic oscillator, and under what conditions it was. He also wanted to show this mathematically. So far what I have is that if there is no damping(friction?) and if the the...
  25. D

    Lightly Damped Simple Harmonic Oscillator

    Tuning forks are lightly damped SHO's. Consider a tuning fork who's natural frequency is f=392Hz. Angular frequency = w = 2(Pi)f = 2463 (rad/s) The damping of this tuning fork is such that, after 10 sec, it's amplitude is 10% of it's original amplitude. Here is my attempt to find the damping...
  26. J

    Simple Harmonic Oscillator: Calculating Particle Position as a Function of Time

    I need someone to please verify my work. Homework Statement A particle of mass m is suspended from the ceiling by a spring of constant k and initially relaxed length l_0. The particle is then let go from rest with the spring initially relaxed. Taking the z-axis as vertically oriented...
  27. snoopies622

    Photon emission from simple harmonic oscillator

    I've looked at a few introductory treatments of the quantum harmonic oscillator and they all show how one arrives at the discrete energy values E_n = ( \frac {1}{2} + n ) hf \hspace {10 mm} n=0,1,2... usually by setting up and then solving the Schrodinger equation for the system...
  28. Q

    Raising and lowering operators on a simple harmonic oscillator

    Homework Statement Hi, I'm currently studying for a quantum mechanics exam but I am stuck on a line in my notes: Ha\left|\Psi\right\rangle =\hbar\omega\left(a^{t}a a + \frac{a}{2}\right)\left|\Psi\right\rangleHa\left|\Psi\right\rangle =\hbar\omega\left(\left(a a^{t} - 1\right)a +...
  29. B

    How Do You Calculate Maximum Acceleration of a Simple Harmonic Oscillator?

    Homework Statement A simple harmonic oscillator has amplitude 0.49 m and period 3.7 sec. What is the maximum acceleration? Homework Equations a(max)=Aw^2 w=angular frequency Vmax=Aw w= angular frequency The Attempt at a Solution I attempted to divide the Amplitude (.49m) by...
  30. N

    Frobenius method aplied to simple harmonic oscillator problem

    Homework Statement P4-1. The Method of Frobenius: Sines and Cosines. The solutions to the differential equation y"+ y = 0 can be expressed in terms of our familiar sine and cosine: y(x) = Acos(x) + Bsin(x) . Use the Method of Frobenius to solve the above differential equation for the even...
  31. D

    Ratio of Kinetic to Potential Energy of Simple Harmonic Oscillator

    Homework Statement Calculate the ratio of the kinetic energy to the potential energy of a simple harmonic oscillator when its displacement is half its amplitude. Homework Equations KE=1/2mv2 = 1/2kA2sin2(wt) U=1/2kx2 = 1/2kA2cos2(wt) KEmax=1/2kA2 Umax=1/2KA2 The Attempt at a...
  32. C

    Simple Harmonic Oscillator - Schrodinger Equation

    Homework Statement One possible solution for the wave function ψn for the simple harmonic oscillator is ψn = A (2*αx2 -1 ) e-αx2/2 where A is a constant. What is the value of the energy level En? Homework Equations The time independent Schrodinger wave equation d2ψ / dx2 =...
  33. I

    Simple Harmonic Oscillator (time independant Schrodingers)

    Homework Statement Particle mass m is confined by a one dimensional simple harmonic oscillator potential V(x)=Cx2, where x is the displaecment from equilibrium and C is a constant By substitution into time-independant schrodingers with the potential show that \psi(x)=Axe-ax2 is a...
  34. B

    Simple Harmonic Oscillator: From Hooke's Law to Harmonious Motion

    Homework Statement Show simple harmonic motion starting from Hooke's Law. The Attempt at a Solution F=-kx =m\frac{d^2x}{dt^2}=-kx \frac{1}{x}\frac{d^2x}{dt^2}=-\frac{k}{m} =\frac{1}{x}\frac{d}{dt}\frac{dx}{dt}=-\frac{k}{m}...
  35. N

    Wave function of a simple harmonic oscillator

    Homework Statement The ground state wave function of a one-dimensional simple harmonic oscillator is \varphi_0(x) \propto e^(-x^2/x_0^2), where x_0 is a constant. Given that the wave function of this system at a fixed instant of time is \phi\phi \propto e^(-x^2/y^2) where y is another...
  36. D

    Simple Harmonic Oscillator Troubles

    Homework Statement This is a 3 part problem, mass M on a spring of length l with mass m. The first part was to derive the Kinetic Energy of one segment dy, second part was to Integrate this and get the Kinetic Energy of (1/6)m(V^2) where V is the velocity of the Mass M at the end of the...
  37. N

    Hamiltonian problem concerning the simple harmonic oscillator

    Homework Statement use the hamiltonian equation H=H_x+H_y+H_z to show that wave functions of the form \varphi(r)=\phii(x)\phij(y)\phik(z) where the functions phi_i(x) are the energy eigenfunctions for a 1-d SHM , satisfy H*phi=E*phi , and find the followed values of E for the 3-d...
  38. F

    What is the Lowest Energy State of a Simple Harmonic Oscillator?

    Homework Statement The wave function \Psi(x,t) ofr the lowest energy state of simple harmonic oscillator, consisting of a particle mass m acted on by a linear restoring force F=Cx, where C is the force constant, can be expressed as.. \Psi(x,t)=Aexp[-(\sqrt{}Cm/2h)x^{}2-(i/2)(\sqrt{}C/m)t]...
  39. T

    Simple harmonic oscillator- the probability density function

    How to find the probability density function of a simple harmonic oscillator? I know that for one normal node is should be a parabola but what is the formula and how do we derive it?
  40. C

    Linear Simple Harmonic Oscillator: period a direct linear proportion to mass?

    If a mass that hangs suspended vertically from a spring is increased, then won't the period increase as a direct linear proportion? (Because the larger mass has a greater inertia and will require a larger force and longer time to change the direction of motion on each oscillation?) Some...
  41. B

    Commutator relations in simple harmonic oscillator

    Homework Statement Show that, [a, \hat H] = \hbar\omega, [a^+, \hat H] = -\hbar\omega Homework EquationsFor the SHO Hamiltonian \hat H = \hbar\omega(a^+a - \frac{\ 1 }{2}) with [a^+, a] = 1 [a, b] = -[b, a] The Attempt at a Solution I have tried the following: [a, \hat H] = a\hat...
  42. A

    Energy of the Simple Harmonic Oscillator

    A 50.0-g mass connected to a spring with a force constant of 35.0 N/m oscillates on a horizontal, frictionless surface with an amplitude of 4.00 cm. Find the speed of the mass when the displacement is 1.00 cm. Can I use here something like : \frac{mv2}{2}=0,5kx2?
  43. C

    Energy of simple harmonic oscillator

    Homework Statement A particle moves along x-axis subject to a force toward the origin proportional to -kx. Find kinetic (K) and potential (P) energy as functions of time t, and show that total energy is contant. Homework Equations K = (1/2)m*v^2 P = (1/2)k*x^2 E = K+P x = Asin(wt...
  44. M

    Simple Harmonic Oscillator question

    Homework Statement A simple harmonic oscillator consists of a block of mass 2.30 kg attached to a spring of spring constant 440 N/m. When t = 1.70 s, the position and velocity of the block are x = 0.135 m and v = 3.130 m/s. (a) What is the amplitude of the oscillations? What were the (b)...
  45. S

    1D simple harmonic oscillator in box

    Homework Statement A particle is inside of a potential described by: H = p^2/2m + 1/2kx^2, x between -L/2 and L/2 H = infinity, otherwise. my task is to compute a first-order approximation to the energies of this potential. The Attempt at a Solution I attempted to use...
  46. C

    Simple Harmonic Oscillator - Hamiltonian

    See post two.
  47. A

    Finding Position of Simple Harmonic Oscillator

    I have been given at t=1.00 a position and velocity. And the spring constant and mass. I have found the maximum amplitude. The question is, where was the block at time t=0? And apparently this can be done without solving for the phase constant and making an equation. The question doesn't...
  48. M

    Deriving Potential Energy and Variance in a Simple Harmonic Oscillator

    Hi all, I have to determine the potential energy of a hanging spring with a mass m in the end and spring constant k. I try to write down the force in the system F = m*g + k*x and integrate the force in order to get the potential energy E_p = m*g*x+0.5*k*x*x Does this look correct...
  49. N

    Simple Harmonic Oscillator Help

    Homework Statement A particle oscillates between the points x = 40mm and x = 160mm with an acceleration a = k(100-x) where k is a constant. The velocity of the particle is 18mm/s when x=100 and zero at x = 40mm and x = 160mm. Determine a) the value of hte constant k, b) the velocity when x =...
  50. K

    Simple Harmonic Oscillator and period

    [SOLVED] Simple Harmonic Oscillator Homework Statement The equation of motion of a simple harmonic oscillator is (second derivative of x wrt t) d2x/dt2 = -9x, where x is displacement and t is time. The period of oscillation is? Homework Equations 2 pi f = omega f = 1/T...
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