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How to find resonant frequency of this spherical mass? [closed]

how to find resonant frequency of this spherical mass in the diagram above? and also, the resonance frequency of mass on an elastic beam with viscoelastic contact with the beam
Hassan's user avatar
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5 votes
5 answers
805 views

How can I interpret the normal modes of this mechanical system?

How can I interpret the normal modes of this mechanical system? The equations of motion for the system are as follows: $$\left[\begin{array}{ccc} m_{1}\\ & m_{2}\\ & & 0 \end{array}\...
fortega20's user avatar
4 votes
3 answers
501 views

Why potential energy is not considered in the internal energy of diatomic molecules?

In thermodynamics, I am taught that there are 5 degrees of freedom in diatomic molecules since there are 3 for translational and 2 for rotational. I interpret degrees of freedom as "ways you can ...
bluesky's user avatar
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-1 votes
2 answers
123 views

Is it possible there can be a non-Fourier model of string vibration? Is there an exact solution?

I am looking for a model of string vibration that does not assume the string is Fourier. Is there a Hamiltonian? The equation of motion must be a function of length and tension, not time, and it must ...
Terence Allen's user avatar
0 votes
1 answer
40 views

Understanding Loop Formation in a Plucked String

I have a question regarding the formation of loops when a string is plucked at different fractional lengths. In a book I referenced, it is stated that plucking a string at 1/6 of its length produces 3 ...
Engr Fahad Safi's user avatar
1 vote
3 answers
64 views

Is sound louder in a solid compared to air?

Consider this experiment, where it is shown that the sound of the metronome is louder when you hold the acoustic sensor directly towards the table. Many explanations in the internet argue that it is ...
Blue2001's user avatar
  • 308
1 vote
2 answers
37 views

Question about waves in a fixed string

consider a string that is fixed at both ends. This string is connected to a metal stick. When I hit the metal stick, sound waves (longitudinal and transversal ?) will propagate trough the metal and ...
Blue2001's user avatar
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0 answers
22 views

How to determine Viscous Friction Damping Coefficient?

I was studying The Simscape Stirling Engine Model and in the Slider Crank - Flywheel part in the rotational damper block, it requires the value of damping coefficient in the script it uses this ...
Sheta's user avatar
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2 votes
0 answers
82 views

Why does $\rm{H_2 O}$ have 12 degrees of freedom?

I know there will be 3 translational D.O.F. and 3 rotational D.O.F., and it can have 4 vibrational D.O.F. (one potential and one kinetic) for each O-H Bond. But from where does 2 more D.O.F. come from?...
Ujjwal's user avatar
  • 41
1 vote
1 answer
22 views

Vibrating Reeds and Pipes

Hold a wooden ruler so it protrudes from a desk top. Flick it, and you get a "twang" sound. The ruler acts like a vibrating reed. Blow across an empty bottle's neck and you get a "...
MRK's user avatar
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0 answers
55 views

Suction Whistles

Dr Theodore Folsom built a Pipe Harmonica (US Patent 2754714, 1952), in which two whistles are attached to a single airway. One whistle is sounded by blowing, the other by inhaling. Sam Hinton can be ...
MRK's user avatar
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0 answers
39 views

How to measure the vibration of an object on a video shot at high speed camere?

I have a video fragment which I split into frames (pictures). I use them in pairs (1 frame with 2, 2 with 3, etc.) to find shifts on x and y axes (i.e. how much I need to shift 1 frame to make it like ...
tryingmybest's user avatar
0 votes
0 answers
33 views

What are the different types of resonances in forced oscillation systems?

I'm currently studying resonances in systems subjected to forced oscillations and have come across various terms and cases that I'd like to understand more clearly. Specifically, I am analyzing a ...
Bananza41's user avatar
0 votes
0 answers
15 views

Molecular stretching oscillations directions

Molecular stretching oscillations directions. If we say that vertical oscillation is up/down. Then, left/right and front/back are horizontal oscillations. Hence, when we measure oscillations of ...
Niss Green's user avatar
2 votes
0 answers
26 views

Frequency, if any, of a string with two different thicknesses [closed]

Very brief question. Assume a string that is made half out of a thin rope and half out of a thick rope (the thick rope is heavier of course). A transverse mechanical pulse is applied at one end (...
glib1's user avatar
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2 votes
3 answers
117 views

Why does the rotational level spacing increase when moment of inertia decrease?

In the rigid rotor approach we obtain the result that the spacing between different rotational energy levels in a particular vibrational state is $\nu = 2B(J+1)$ and $ B = \frac{ h }{ 8 \pi^2 Ic }$, ...
aetherflo's user avatar
0 votes
0 answers
68 views

Carbon dioxide vibration

Can we induce antisymmetric stretching vibration in carbon dioxide molecules by collision with nitrogen molecules in air at standard temperature and pressure?
Stan Tarka's user avatar
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0 answers
23 views

Vibrating object on optical table

Wikipedia says this about optical tables: Many optical systems require that vibration of optical elements be kept small. As a result, optical tables are typically very heavy and incorporate vibration ...
Riemann's user avatar
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2 votes
0 answers
36 views

Frequence vs speed of a moving object

Imagine swinging wood stick using hand (say it's a 1-meter long cylinder with 2 centimeter diameter, just for the sake of argument). When doing it fast (angular velocity = $\omega_1$), it will create ...
h218614's user avatar
  • 21
0 votes
2 answers
47 views

Quantum position in molecular vibration

Evere molecule consists of atoms that vibrate around their equilibrium positions. This can be viewed from a classical or a quantum perspective. However, I found a seeming inconsistency between these ...
Riemann's user avatar
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2 votes
1 answer
37 views

How do the amplitudes of longitudinal wave harmonics in a string vary with excitation (pluck) position?

A very good explanation for the amplitudes expected for each harmonic of an ideal string with a transverse excitation is included here. The final equation given is: $$b_n = \frac{2AL^2}{\pi^2\ell(L-\...
mike's user avatar
  • 321
2 votes
0 answers
54 views

Vibrating string and damping

Suppose we have a string (in tension) with its ends fixed. Think of a guitar string. Suppose we start with a plucked initial position and we let the string free. If we use the wave equation: $u_{tt}=c^...
Plemath's user avatar
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1 vote
1 answer
55 views

String vibration dimensions

We're all familiar with the typical diagrams of standing waves of a string, as in this image from Wikipedia: The thing that bothers me is that they ignore the reality that the string is vibrating in ...
Eric Singer's user avatar
0 votes
1 answer
94 views

1D Wave equation with free end: limitation of Neumann's boundary condition?

Consider a slinky whose one end is fixed and the other is free. The textbook approach for analyzing its longitudinal vibrations is to use the wave equation along with Neumann's boundary condition, i.e....
Plemath's user avatar
  • 208
0 votes
0 answers
29 views

Frequency of vibration of rod

Imagine you have got a metal rod of length $l$ and the left side of the rod is fixed, and the rod is pointing in the direction of the x-axis of an imagined coordinate system. At distance $d$ from the ...
Michael S's user avatar
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1 vote
0 answers
43 views

Spoon with Marmalade in Space [closed]

I sit in a space shuttle in zero gravity condition. I have a spoon in one hand and the jar of marmalade in the other. I take marmalade with spoon. If I shake it very hard, will the marmalade detach ...
E.Z's user avatar
  • 111
0 votes
1 answer
45 views

How can I get sound spectrum data of instruments?

I am trying to generate a piano noise by a python function. ...
1 vote
0 answers
9 views

If something is rigidly attached to a vibrating part, does the number of contact points effect the vibration transfer?

I have an enclosure mounted to the chassis of a vehicle. There are multiple points where the enclosure is fastened to the chassis as well as areas where it rests on the chassis without being fastened. ...
Owen Li's user avatar
  • 11
0 votes
1 answer
96 views

Is sound essentially motion?

From my understanding, the only way for humans to create sound is by moving our bodies, vocal cords, or by moving other objects. So depending on how fast we or other objects can move, different ...
Lecifer's user avatar
  • 109
0 votes
0 answers
45 views

Picturing a normal mode of vibration of the monoatomic lattice in 1D that is either in-phase nor completely out-of-phase

For a monoatomic lattice of $N$ atoms in one-dimension, the ratio of the displacements of two consecutive atoms at the $(n+1)$th and the $n$th site is given by $$\frac{u_{n+1}}{u_n}=e^{ika}$$ where ...
Solidification's user avatar
0 votes
2 answers
101 views

Does rhythm create pitch?

As in, matter (a physical object) that is vibrating = a pitch And secondly If we calculate bpm with a “tick” which is just indefinite pitched percussion, how does an indefinite pitched beat compare to ...
Lecifer's user avatar
  • 109
0 votes
0 answers
56 views

Amplitude of the steady-state response to undamped spring-damper system subject to forcing function $p_oe^{-at}$

I am trying to find the amplitude of the steady-state solution to the following undamped equation of motion: $$m \ddot{u} + k u = p_0 e^{-at}$$ The question is asking to prove that the steady-state ...
Luminbox's user avatar
1 vote
0 answers
54 views

Is it possible to use audio to make a liquid (such as water) resonate? [closed]

I am a graduate student studying wireless perception, and recently I want to carry out liquid recognition. I want to use a speaker as a sound source to generate vibrations (by playing sounds of ...
Muller Thomas's user avatar
1 vote
0 answers
44 views

The definitions of coherent phonons and acoustic phonons

I found that the definition of coherent phonon: A femtosecond laser pulse can initiate collective, in-phase atomic motions in solids called coherent phonons. My question is: what is the difference ...
MathJacky's user avatar
1 vote
0 answers
27 views

Can someone please explain how is the setup stated below apparently causing amplitude resonance in spite of different frequencies?

Suppose I have a pendulum such that its natural frequency is $2 Hz$. I release it from One extreme by striking it with a tuning fork of frequency $1 Hz$. Now in $0.5s$, the pendulum will undergo 1 ...
Shirshayu Sarkar's user avatar
1 vote
0 answers
26 views

Are Harmonic or Subharmonic resonance the only outcomes for a system with applied vibrations?

I'm working on performing a linear stability analysis on a system with fluid undergoing applied vibrations. Now, usually these systems are analyzed with no fluid velocity. Under these conditions, it ...
Daniel Harper's user avatar
1 vote
0 answers
57 views

Phonon eigenfrequencies under time reversal

In G. P. Srivastava's "The Physics of Phonons", 1e., the ansatz which solves Newton's second law in the harmonic approximation is taken to be $$ u_\alpha(\ell b;t) =\frac{1}{\sqrt{m_b}}\...
CW279's user avatar
  • 349
1 vote
1 answer
92 views

How to interpret huge number of phonons?

In my condensed matter class we have seen how to treat the problem of vibration in a lattice in quantum mechanics. After heavy calculation we derive that the number of phonons with a given crystal ...
CoolerThanACooler's user avatar
2 votes
1 answer
113 views

Anharmonic effects in crystals, help with intuition

I've been reading a bit about how it is necessary to consider anharmonic effects in crystals if one wants to properly understand things like thermal expansion etc. So for example here: So the cubic ...
JPP's user avatar
  • 23
1 vote
1 answer
177 views

Modes of vibration

I've been thinking that 'modes of vibration' refers to the frequencies which produce standing waves in a system. But now I'm confused, because ChatGPT gave me the below response for my question. ...
Vivek karunakaran's user avatar
23 votes
4 answers
3k views

Magnetic field changes induced by vibrating electric guitar string

Here is a picture (from a paper by Feinberg and Yang in the Journal of the Acoustical Society of America) of an electric guitar string vibrating (mostly in the $y$ dimension) near a permanent magnet. ...
Wandering Logic's user avatar
2 votes
1 answer
27 views

Calculating vibrational mode coefficients of a drum for an arbitrary excitation

I am interested in the modes of a rectangular drum of size WxL that is fixed on 4 edges. The differential equation that governs the vibrations of a 2D membrane is $\nabla^2 \phi - \frac{1}{c^2}\frac{\...
Gappy Hilmore's user avatar
0 votes
1 answer
39 views

Do vibrational frequencies produced from sound pass through your entire body? from one side to another? [closed]

when there is a noise by me, i feel the vibration on my skin from the direction it’s coming, it moves into my body. a wall of what sound would feel like passing through me. i perceive it as container ...
na.arah's user avatar
0 votes
1 answer
146 views

Fourier transform for diagonalizing the Hamiltonian of lattice

I am reading the first chapter of "Statistical Theory of Fields" by Kardar. There he discussed the idea of phonons. Consider an ideal lattice at zero temperature with lattice vectors $\vec q^...
Iti's user avatar
  • 436
2 votes
1 answer
289 views

Sum of incident and reflected waves being the transmitted waves amplitude

Suppose we have an incident wave $\psi_i$ heading towards an interface, then when it reaches the interface it is split into a reflected and a transmitted wave: $$ \psi_i \to \psi_r + \psi_t $$ Why ...
jay53892's user avatar
0 votes
1 answer
223 views

Coupled pendulum question about equations of motion [closed]

I am working on problem number 2.3 of the Franklin, Powell, Naemi book Feedback Control of Dynamic Systems. The problem uses the simple coupled pendulum system below, where the two pendulum masses are ...
krishnab's user avatar
  • 181
1 vote
1 answer
746 views

What exactly are sympathetic vibrations?

On every source and in every example, it seems that sympathetic vibrations are quite directly linked to or are the same as resonance. The classic example of sympathetic vibrations is of two similar ...
Kayen Jain's user avatar
1 vote
1 answer
122 views

How to test resonance frequency of spring using sound?

I've done experiment with spring and mass to determine the natural frequencies of 4 springs. The first experiment went well but I had some problem when I want to test the resonant frequency. I'll ...
Rizky Aiman's user avatar
1 vote
0 answers
87 views

How would you experimentally determine the damping coefficient of a system?

We have a suspended beam that we need to determine the natural frequency, and more importantly the damping, of. To avoid resonance. The geometry of the beam is a little too complex to rely on theory ...
BoddTaxter's user avatar
  • 2,878
0 votes
2 answers
93 views

Does vibrational energy transfer to translational energy when an excited $\rm CO_2$ molecule collides with an $\rm N_2$ or $\rm O_2$ molecule?

My understanding is that when a $\rm CO_2$ molecule absorbs a photon of heat in the atmosphere after some time it simply re-emits that photon in a random direction. If that photon makes it back to its ...
Michael D Mays's user avatar

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