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4
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3answers
255 views

Non-SHM oscillatory motion

How to solve these kind of questions , where $|F| \propto x^2$? How to find time period and velocity type related things to the oscillatory motion? ...
3
votes
1answer
457 views

Simple pendulum period in three different cases

Imagine you have a simple pendulum hanging on the ceiling of a train which has a period called T. How will the period be in the following cases: When the train is in circular motion in a curve of ...
9
votes
3answers
1k views

What is the period of a physical pendulum without using small-angle approximation?

What is the expression for the period of a physical pendulum without the $\sin\theta\approx\theta$ approximation? i.e. a pendulum described by this equation: $$ mgd\sin(\theta)=-I\ddot\theta $$ ...
1
vote
2answers
718 views

Why is simple harmonic motion called so?

Is the motion of a simple pendulum, a simple harmonic motion? It stops vibrating after sometime.
1
vote
2answers
287 views

Motion of a pendulum

The equations of motions for a simple pendulum is given by $$\ddot{\theta} ~=~ -\frac{g}{\ell}\sin(\theta),$$ where $g$ is acceleration due to gravity and $\ell$ is the length of the pendulum's ...
2
votes
3answers
259 views

Condition for closed orbit [closed]

I'd like to know when an orbit is closed. I know that, to have a closed orbit, there is a ratio that must be a rational number, but I don't know other things..
3
votes
1answer
150 views

Why don't we use quater-circular dees instead of semi-circular dees in a Cyclotron

This is the setup, I have in my mind: O1, O2, O3 and O4 are 4 oscillators. The arrows in between the Dees represent the alternating EMF the Oscillators will generate. I think we can easily adjust ...
2
votes
1answer
1k views

How do I account for the direction of friction acting on a spring?

I would like to set up the equations of motion for a simple spring oscillator. Let's have a spring lying horizontally; we attach a small mass $m$ to the (massless) spring. The force of the spring ...
2
votes
2answers
5k views

Phase difference of driving frequency and oscillating frequency

If a mass is attached to a spring and is oscillating (SHM). If a driving force is applied it must be at the same frequency as the mass's oscillation frequency. However I'm told that the phase ...
1
vote
0answers
339 views

Normal modes of oscillation: how to find them

Are normal modes the eigenvectors of the matrix $(\omega ^2 T- V)$ where $T$ is the matrix of kinetic energy and $V$ is the matrix of potential energy? Is it the only way to express them? How can I ...
3
votes
2answers
209 views

“Inverted” quantum oscillator

I'm trying to understand the problem of the "inverted" oscillator, which has the following Hamiltonian: $$ \hat{H}=\frac{\hat{p}^{2}}{2m}-\frac{k\hat{x}^{2}}{2} $$ Suppose that a particle at the ...
1
vote
2answers
200 views

Small Oscillations and matrices: suggestion about text

I'm undergraduate and I'm looking for a text about Small Oscillations in which matrices are used. Could you suggest me a book or a PDF file?
1
vote
1answer
428 views

Symbol for dashpot/damper (in a harmonic oscillator)

In diagrams that contain the dashpot symbol, sometimes the mass is attached to the "interior" end of the dashpot, other times the mass is attached to the "base" end. For example, consider the ...
2
votes
0answers
97 views

After quantization of electron vibrations, do we need electrons anyway?

The title question is not ment in a general context, but one in which goes to the plasmon theory. In that case, how is are the statistics (boson vs. fermions) of plasmons determined? And is there an ...
0
votes
1answer
1k views

How the frequency of the oscillation is affected?

Is the frequency of oscillation of a rotating disk affected if a mass hanging from (attached to the disk but pulled by gravity) the disk exerts a torque on the rotating disk?
2
votes
2answers
452 views

Why do joined massless springs, act like a rope under tension?

In an oscillations exercise there is a spring attached to another spring, attached to a block. Long story short: I have to find the global $k$. In the solutions it says: "Because the springs are ...
2
votes
3answers
889 views

How does energy depend on frequency in an alternating current circuit?

In what relation is the energy input in an alternating current circuit to its frequency? I'd guess I have to compute something like $$E=\int P(\omega,t) dt=\int U(\omega,t) I(\omega,t) dt, $$ but ...
0
votes
0answers
80 views

Springs yet again, this time with a picture. Infinite displacement, makes no sense [duplicate]

Possible Duplicate: How could this damped oscillator ever go to infinity? Or negative infinity for that matter? Consider this ! Where I purposely drew the right arrow bigger than the left ...
0
votes
2answers
946 views

How does the Milkovic Two-Stage Mechanical Oscillator Pendulum-Lever System work?

See http://peswiki.com/index.php/Directory:Milkovic_Two-Stage_Mechanical_Oscillator The Two-Stage Mechanical Oscillator Pendulum-Lever System is very simple, yet very puzzling because it appears ...
2
votes
3answers
9k views

When are Maximum Velocity and Acceleration acheived in Simple Harmonic Motion?

Im trying to get my head around SMH out of curiosity because it seems simple yet I'm not getting the concept behind some ideas. For a SMH equation : $$ x=a \sin(\omega t+\phi) $$ Under what ...
0
votes
1answer
5k views

Finding Phase angle of Simple Harmonic Motion?

A sinusoidal oscillator has : $$x=x_{max} \cos(\omega t - \varphi )$$ Period is 2, initial displacement is 100mm initial velocity is 200mm/s What is the phase angle assuming $-\pi < \varphi < ...
1
vote
2answers
509 views

How could this damped oscillator ever go to infinity? Or negative infinity for that matter?

This is an ODE problem,but I cannot visualize why it can go to infinity or negative infinity. Consider $$x'' -6x' + 8x = 0$$ Where $x''$ is acceleration, $-6x'$ is the ...
0
votes
1answer
531 views

What makes up a resonator of radio?

I was reading this article about resonators. Quote: The sine wave that matches that particular frequency will get amplified by the resonator, and all of the other frequencies will be ...
1
vote
3answers
245 views

Quality factor for a quantum oscillator?

I've been reading papers about nanomechanical oscillators, and the concept of quality factor often pops up. I understand to some extent about Q factor in classical sense, but since nanomechanic ...
1
vote
0answers
158 views

Conveyor scales modeling

Assume we have a conveyor scales. Which consists of scales, and motor with conveyor belt placed above, so that the boxes can be measured (weight) while moving above. What I want is to create the model ...
0
votes
1answer
1k views

How does the X-Y mode of an oscilloscope work?

I recently used an oscilloscope in X-Y mode to draw the phase ellipsis of two voltages. I then used the formula phi = arcsin(2y/B) where y is the value of the ellipsis at x = 0 and B is the total ...
6
votes
2answers
361 views

Conservation of energy in a non-linear oscillator

I have a homework question about a "non-linear oscillator". I actually have an answer to this question, but the answer I get is stronger than what is needed according to the question. The question ...
1
vote
1answer
425 views

Help understanding this forced undamped oscillator

I have a forced oscillating system, with driving force as $f_0\cos\omega_0 t \cos \delta t$ giving the equation of motion: $$\ddot{x}(t) +\Gamma \dot{x}(t) +\omega_0^2x(t) = f_0\cos\omega_0 t \cos ...
5
votes
1answer
10k views

How do I solve for the phase constant given the amplitude and the angular frequency?

A piston (with mass M) in a car engine is in vertical simple harmonic motion with amplitude A. The engine is running at a period T. Suppose a small piece of metal with mass m were to break ...
3
votes
1answer
524 views

Numerical computation of the Rayleigh-Lamb curves

The Rayleigh-Lamb equations: $$\frac{\tan (pd)}{\tan (qd)}=-\left[\frac{4k^2pq}{\left(k^2-q^2\right)^2}\right]^{\pm 1}$$ (two equations, one with the +1 exponent and the other with the -1 exponent) ...
2
votes
2answers
466 views

Wave equations & propagation theories

I'm interrested in making computer simulation but I've run into rather physics oriented problem. I have to choose how to propagate my wave. Though I've found technique called FDTD (finite-difference ...
3
votes
0answers
2k views

Energy Levels of 3D Isotropic Harmonic Oscillator (Nuclear Shell Model)

One simple way of detailing the very basic structure of the nuclear shell model involves placing the nucleons in a 3D isotropic oscillator. It's easy to show that the energy eigenvalues are $E = ...
9
votes
2answers
840 views

Quantum shot-noise and the fluctuation dissipation theorem

Classically, shot noise observed in the signal generated by a laser incident on a photodiode is explained as being due to the quantization of light into photons, giving rise to a Poisson process. In ...