The tag has no wiki summary.

learn more… | top users | synonyms (2)

0
votes
0answers
31 views

Entropy of an oscillator in Einstein's solid

This is a homework problem and I need help with it. A solid's (Einstein's model) oscillators are in the first excited state on average. How much entropy does one oscillator have? What I've tried so ...
0
votes
2answers
65 views

Physical interpretation of initial conditions for damped mass-spring system

I have background in pure mathematics so my question is about physical meaning. If we consider equation for damped mass-spring system, it is linear ordinary second order differential equation. So to ...
10
votes
1answer
400 views

Small oscillations of heavy string

I'm solving problem in classical field theory and I have some difficulties. I'm trying to study small oscilations of heavy string with fixed points. First of all I wrote down this Lagrangian: ...
4
votes
1answer
109 views

Caldeira-Leggett Dissipation: cannot get it

I am trying to understand the Caldeira-Leggett model. It considers the Lagrangian $$L = \frac{1}{2} (\dot{Q}^2 - (\Omega^2-\Delta \Omega^2)Q^2) - Q \sum_{i} f_iq_i + \sum_{i}\frac{1}{2} (\dot{q}^2 - ...
17
votes
8answers
2k views

Why are sine/cosine always used to describe oscillations?

What I am really asking is are there other functions that, like $\sin()$ and $\cos()$ are bounded from above and below, and periodic? If there are, why are they never used to describe oscillations in ...
1
vote
1answer
113 views

Oscillation of a Bose Einstein condensate in a harmonical trap

We were asked to try to make a theoretical description of the following phenomenon: Imagine a 2D Bose Einstein condensate in equilibrium in an harmonical trap with frequency $\omega$. Suddenly the ...
2
votes
1answer
68 views

Tuned Mass Damper

I was learning about the different applications of resonance and one of them is the tuned mass damper used in buildings. One thing I am confused about is as to why the mass attached to the building ...
1
vote
0answers
24 views

Methods for quantifying a network of coupled oscillators

I usually am more on the statistics part of things, so pardon my misuse of the terminology. I am simulating a network of non-pulse coupled non-linear oscillators ( I am not sure what the correct term ...
2
votes
1answer
163 views

Synchronizing Pendulums

Assume we have a frictionless pendulum of length $l$ with mass $m$. This pendulum hangs from some weightless contraption, which is itself bolted to a platform. This platform can move horizontally in ...
4
votes
2answers
116 views

Synchronization phenomenon: A simple explanation?

Being from a mathematical background, physicists' intuitive arguments always seemed challenging for me to follow. I am currently reading a book called "Synchronization: A Universal Concept in ...
1
vote
1answer
27 views

How to calculate required energy to displace a pendulum?

How can one calculate the amount of energy needed to displace pendulum with given mass m and string length L to $\alpha$ degrees from resting position when acceleration due to gravity is known?
2
votes
1answer
30 views

What is the exact relation between a real oscillating body's time period with time?

I took an empty bottle and placed it on the floor, then tilted the bottle to one side such that the the displacement caused a disturbance in its balance but not enough to completely tilt it over. The ...
3
votes
1answer
123 views

Is using a swing an example of normal or of parametric resonance?

Parametric resonance is a situation where the driving frequency is a multiple of the eigenfrequency. Various people say that using a swing and propelling it oneself is such a case, with the driving ...
1
vote
0answers
36 views

What would happen if…? (Scenarios involving a ball in an electric field) [closed]

First I shall define two table tennis balls: Ball $A$ is coated with a conducting material and ball $B$ is an insulator. Then I'll define two scenarios: Scenario $I$ is a ball held from a ...
1
vote
1answer
94 views

Meaning of “Simple” in Simple Pendulum and Simple Harmonic Motion?

I have gone through the Phys.SE question Why is simple harmonic motion called so?. From the 1st answer of this Question it seems to me that another type of "Harmonic motion" is "Damped Harmonic ...
0
votes
2answers
73 views

Why does the coil in this apparatus reverse its direction of oscillation?

I've been given some notes and I have to 'unscramble' them and put them in order. They are supposed to describe what happens in the diagram below: The notes to unscramble and form a proper answer ...
0
votes
1answer
50 views

Question about pendulum

I came up with this problem by myself: How much force do I need to make a pendulum revolve? Now I imagined that the force $\vec{F}$ must be enough to make the pendulum swing until half of the ...
1
vote
0answers
26 views

Is having full information about the resonances of a rigid body equivalent to having full information about its material parameters?

Lets say I have a mechanical system whose mechanical resonances (mode shape and frequency) I can measure with perfect accuracy. Is this theoretically equivalent to knowing the materials parameters, ...
1
vote
0answers
27 views

A voltage-controlled oscillator? [closed]

I already apologize for my medium english... I'm a french guy, not really gifted to recognize electronic circuits : In fact, I need to identify a circuit from is function. So, here is the block ...
1
vote
1answer
38 views

Normal mode of a coupled pendulum: why the constant $\psi_1$, $\psi_2$

I need to solve a problem that tells me to find out the motion of both the pendulums that appear in the first 45 seconds of this video I think this kind of motion is described by a system 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: $$ mgd\sin(\theta)=-I\ddot\theta $$ ...
0
votes
1answer
55 views

Pendulum Confusion

This text in my book is pretty confusing:With my emphasis A simple pendulum is a heavy point mass (bob) suspended from a rigid support by a massless and inextensible string. This is an ideal case ...
0
votes
0answers
31 views

Transfer Equation between two oscillating pendulum collision

How to model the energy transfer equation between two oscilators colliding? For example two pendulum oscilating at frequency $f_1$ and $f_2$ and they transfer energy during colision.
0
votes
0answers
60 views

Coupled Oscillation Simulation

I'm looking for an online coupled oscillation simulation. The best I have got so far is this --- https://phet.colorado.edu/sims/normal-modes/normal-modes_en.html But I'm looking for something which ...
1
vote
1answer
117 views

Why maximum energy transfer at natural frequency even if max amplitude occurs below $f_0$

This is a paragraph from my book: "For a damped system, the resonant frequency at which the amplitude is a maximum is lower than the natural frequency.However, maximum transfer of energy, or energy ...
0
votes
1answer
64 views

Does sound absorption depends upon the amplitude of sound wave?

I can understand the mechanism of frequency dependant sound absorption by most materials but does the sound attenuation also depends upon the AMPLITUDE(sound pressure or rather loudness/sound ...
0
votes
0answers
80 views

More on the closed-form for a simple pendulum

I've learnt about the simple pendulum, and while the regular curriculum only uses the linear approximation of $\sin\theta$ to obtain $\ddot\theta+\omega_0^{2}\theta=0$. I tried to find out about a ...
0
votes
1answer
75 views

Derivation of Foucault pendulum [closed]

Let us define our usual Cartesian coordinates ($x'$,$y'$,$z'$), and let the origin of our coordinate system correspond to the equilibrium position of the mass. If the pendulum cable is deflected from ...
2
votes
3answers
7k 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
2answers
312 views

Rabi oscillations and two level dynamics

I'm currently looking at Rabi Oscillations, and not I have a look at the following equations: $$W = \sqrt{\Omega^2+\delta^2}.$$ The amplitude: $$\frac{|\Omega|^{2}}{\delta^{2}+|\Omega|^{2}}$$ Now, ...
1
vote
0answers
53 views

stopping, moving of mobile phone when vibrating

A mobile phone move aside when it vibrates. How is that happening ? and most importantly is it possible to make any changes to the vibration motor to stop moving when vibrating or any other methods to ...
1
vote
0answers
44 views

“Forgetting” the initial condition in conservative oscillations; What has been “forgotten” exactly?

I am training myself on oscillations. The topic is self-sustained oscillations. The claim is these oscillations are NOT forgetful about their initial condition as opposed to conservative oscillators ...
1
vote
3answers
42 views

What are the means to consider that a specific function is phase of an oscillator?

I hope the experts of the field forgive me for this n00b questions, but I am just trying to understand physics. Assume the following function: $$\phi(t)=\omega t+\cos(\omega t)$$ The above function ...
5
votes
2answers
88 views

Is it possible to find a “replacement pendulum” for a system of two equal but perpendicular pendulums?

I ask this question, because at the end of this long day I'm just too dazed to derive the proofs myself (even though I know that I should feel ashamed for this). So, the question: Given two ...
8
votes
2answers
2k views

What creates the chaotic motion on a double pendulum?

As we know, The double pendulum has a chaotic motion. But, why is this? I mean, the mass of the two pendulums are the same and they have the same length. But, what makes its motion random? I'm just ...
2
votes
2answers
133 views

Harmonic Oscillator driven by a Dirac delta-like force

Consider that there is no damping for simplicity. As we know, a driving force of the form $\sin(\omega t)$ will make the oscillator at steady state vibrates at the external frequency $\omega$. What ...
1
vote
1answer
45 views

Why can we use the energy of a pendulum to calculate its frequency?

The question might sound rather vague; to calculate the frequency using the energy we simply use that the total energy is constant, set the derivative to zero and solve the equation of motion that ...
1
vote
2answers
93 views

Energy of a damped oscillator

$$ E=\frac{1}{2}m\left(\frac{dx}{dt}\right)^2+\frac{1}{2}m\omega_0^2x^2. $$ This is the equation for the energy of a oscillator. The second term is the potential energy. Now, my question is, will ...
4
votes
2answers
72 views

Definition of quantum anharmonicity

I have been reading research papers in mathematical physics for some months now, and I've seen the the term "anharmonic oscillator" quite frequently. At first I assumed that given a Schrodinger ...
2
votes
1answer
109 views

Principle of Superposition for driven oscillator

So I understand the the Superposition Principle states that all the forced oscillations, as determined by multiple external forces, are to be added up in order to get the entire solution. However, ...
4
votes
2answers
101 views

How can I find the amplitude?

Prove that the motion of a mass $m$ on a linear spring with constant $k$, has the form $$y (t) = A \sin(wt+f),$$ where $t$ is the time and $A, w, f$ are constants. We know that for $t = 0, y(0)=y_{0}$ ...
0
votes
1answer
69 views

How to include Damping in a Simple harmonic oscillator

Im designing a model for Kelvin Method. Some of my calculation results are as follows: Radius of the membrane : 50 micron thickness of the membrane : 3.25 micron resonate frequency : 1.32MHz ...
-1
votes
1answer
73 views

Oscillator, angular frequency equation

I found the highlighted equation on the Wikipedia on angular frequency, however it doesn't say how it was obtained, could someone please explain that? Also, it says that the spring is massless, if ...
1
vote
1answer
32 views

Lagrangian Oscilattor

I want to know how to calculate the normal modes from a Lagrangian. I make the T (kinetic energy matrix) and U (potential energy matrix), and then I calculate the determinant of $|T-\omega ^2 U|$ ...
1
vote
1answer
314 views

Compound pendulum clarification?

I read in a book the following about compound pendulum and small displacements: There are two points only for which the time period is minimum. there are maximum 4 points for which the time ...
1
vote
3answers
122 views

Why do degenerate normal modes appear as complex conjugate pairs?

Can anyone prove this? THE DETAILS Suppose we have a system with n components, (i.e. $|~{\psi}(t)\rangle=\sum \langle x_i|~\psi(t)\rangle ~|~x_i\rangle$) where our equation of motion is described ...
2
votes
1answer
78 views

Nature of motion of a pendulum

Consider a pendulum suspended from the ceiling of a lift in free fall , if its displaced from its mean position , what will be its nature of motion? what i thought was that it would simply stick to ...
3
votes
2answers
322 views

Oscillation of a rolling sphere in a bowl [closed]

This is a homework task. I already came to a result but I am very unsure. The task: In a bowl with the shape of a semi-circle ($R$ = 0.5m) a sphere (there is no specification for the size of the ...
2
votes
1answer
71 views

Neutrino mass and energy question

If a neutrino has mass then it travels less than the speed of light. Suppose I boost myself to the rest frame; i.e. bring it to rest in the laboratory. Now if it oscillates between different states ...
0
votes
1answer
49 views

Oscillation Question [closed]

Now normally (if it was a block not rotating) all you would have to do is use $w^2 = k/m$ and $E= \frac12k(A\cos(2wt+\theta))^2 + \frac12m(Aw\sin(wt+\theta))^2$ or in other words the translational ...