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1answer
33 views

Muting a bell with a resonating object

I recently moved into an apartment next to a church with bells and since then I haven't stopped dreaming of ways to mute them. I've been thinking about a design but I'm a little unsure of the ...
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1answer
56 views

Undamped Resonance of a Classical Harmonic Oscillator

Consider an undamped harmonic oscillator. It may be driven at it's natural frequency, $\omega_0^2 = \frac{k}{m}$. According to Feynman, and other sources, were this to happen, the amplitude of the ...
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1answer
187 views

Why does at resonance only, potential energy is equal to kinetic energy?

At the steady state, the average stored energy is given by $$E = \dfrac{1}{2} m\left\langle (x')^2\right\rangle + \dfrac{1}{2} m{\omega_0}^2 \left\langle x^2 \right\rangle$$ They become equal when ...
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2answers
226 views

What is the qualitative cause for a driven oscillator to have a max. amplitude during resonance?

The steady-state motion of a driven oscillator is given by;$$x =\underset{\text{amplitude}} {\dfrac{F_0}{m({\omega_0}^2 - {\omega}^2)}} \cos\omega t.$$ As we see, the amplitude becomes maximum when ...
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2answers
495 views

What is the essential difference between a resonance and a particle?

Let me start by explaining my particle physics background is very patchy, so this question may not be as coherent as I would like it to be. In general terms, what is the difference between a ...
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2answers
164 views

Resonance in Benzene violating Second Law of Thermodynamics

In chemistry a few months ago we were taught the resonant structure of benzene, that states the double bonds upon the six carbon atoms flicker back and forth between the two possible states it can be ...
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3answers
227 views

Materials that change their natural frequency

Say I have some material (solid, liquid, plasma, etc.). It has a set of natural frequencies. Now I pass a wave through it (sound, light, etc.). Once I pass the wave thought it, the material has a ...
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0answers
108 views

What is the mechanism of subharmonic oscillations?

It's clear to me from linear systems theory that energy manifested within a fundamental mode of resonance can saturate with the excess energy spilling over into harmonic frequencies greater than the ...
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0answers
60 views

Exploiting Resonance to Make a Bound State with Gamma Rays (and other Very High Energy Particles)

One obvious consequence of any finite potential is that a high enough energy wave-function will not form a bound state, either they are high enough energy they will generally just bypass the barrier ...
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2answers
94 views

Other frequencies and breaking glass

I know an individual can use the natural frequency of glass to break it, but is it possible to break glass with a frequency other than the natural frequency? Will the glass still vibrate if the ...
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2answers
84 views

Quality Factor in a Parallel LC Circuit

I was wondering if there is a notion of a quality factor in a parallel LC circuit, since there is no resistance. One can show that this circuit has a resonance frequency as follows: Impedance: ...
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2answers
61 views

Resonance peak broadening due to losses: physical reason

I wonder why when losses are present in a oscillator, the width of the resonance peak is broadened. More precisely: why, when losses are present, can the amplitude reach nearly the maximal one (the ...
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2answers
124 views

Physical reason behind having greater amplitude when driving frequency$ < $ natural frequency than that when driving frequency $>$ natural frequency

This is quoted from A.P.French's Vibrations & Waves: If the driving force is of low frequency relative to the natural frequency, we would expect the particle to move essentially with the ...
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1answer
102 views

Finding the frequency of vibration of part of a system

The setup: 4 spheres of diameter $d$ are suspended on a horizontal plane (magically). They are arranged in a square with length $l$ (the vertices are correspondent to the sphere's centers). The ...
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2answers
77 views

In general terms, what key elements are necessary for resonance to exist in a physical system?

I found a related question An Analogy for Resonance, and John Rennie gives a good explanation using description of the harmonic oscillator. But I'm really looking for an accurate and complete list of ...
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1answer
63 views

Can someone give an intuitive understanding of Fano Resonance?

I'm reading about Fano Resonance. The line that almost every source I can find gives is something like (from the wiki): The Fano resonance line-shape is due to interference between two ...
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2answers
242 views

Does every object, every particle and every thing have it's own resonant frequency?

The principles of resonance are such that the greatest amplitude of a vibrational or electrical wave peak at a certain frequency, and they peak while consuming less power overall to maintain it. I'm ...
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1answer
73 views

Feynman Lectures: Resonance - Problem with Formula

I am reading Volume 1 Chapter 23 of FLP, and I have come across something rather strange. Feynman says that: $$ \rho^2 =\frac{1}{m^2[(\omega^2-\omega_0^2)^2+\gamma^2\omega^2]} $$ A graph of this can ...
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2answers
628 views

What really happen with resonance inductive coupling

I can't figure out the picture of resonance inductive coupling I can image how magnetic inductive coupling works, It scatter magnetic around one coil and if second coil being near it then induce ...
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0answers
48 views

Metastable bound state in resonance scattering

In resonance scattering, why does the mean lifetime of the "metastable" bound state depend inversely on the width of the resonance?
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3answers
172 views

How does the voltage across an inductor and a capacitor vary in series LCR circuit about resonance?

I am aware that at resonance, the voltage across the inductor and the capacitor are equal in magnitude and opposite in phase. However, I want to know how the voltage across $L$ and $C$ vary if I vary ...
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2answers
121 views

Singing for physicists: How to resonate by body cavities with my voice?

My body has various cavities, such as my throat, mouth, chest, and nose. This cavities have resonant frequencies. I also have a voice box, which creates sound. How do I create sounds at the resonant ...
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3answers
636 views

What are the rules for breaking a glass with your voice?

So, this morning I woke up and remembered something I discussed about with one of my friends: Can human voice really break a wine glass? So I looked it up and after checking many websites and ...
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1answer
111 views

Reflection of Sound wave (Pressure Wave)

I want to study about the phenomenon of reflection of pressure waves as in an open ended organ pipe. Please suggest a suitable resource? I know about the harmonics in a stretched string and I can use ...
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2answers
154 views

How can I easily measure the distance between well head and water surface continuously

Reprhasing the question is a more open ended manner: Method 1: Use a pipe and measure it's resonance. Given a closed pipe from 10 to 300 feet in length, and roughly 5/8" in diameter, made of 1/16" ...
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1answer
248 views

The demise of the Tacoma Narrows bridge was casused by aeroelastic flutter. But isn't that just a special case of resonance?

Much of the research I've done on the Tacoma Narrows bridge disaster of 1940 attribute the collapse of the bridge due to aeroelastic flutter - not strucural resonance. But isn't aeroelastic flutter ...
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1answer
78 views

What is the source of energy in this system? (resonance realated)

This is curiosity question, sorry if description is too vague. Suppose we have a string attached to some small frame on both sides Then we apply a force by plucking it with a finger, lets say 5.0 N ...
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1answer
125 views

Amplitude-Frequency curve

Given a resonance curve just like this: Could someone explain to me what the physical meaning of the intersection with the ordinate is? At first glance I would say it has to be $(0 | 0) $ since ...
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2answers
350 views

relationship of number of standing waves with Temperature?

If we have let us say fixed air column of length 'L', in a open-closed column problem, lamba is equal to 4*L/(2n-1). n = number of nodes / anti nodes in air column How does 'n' changes with ...
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1answer
330 views

What's the difference between NMR and EPR?

Both NMR and EPR describe the response of magnetic spin to external field. When collecting data, how do you know you're looking at nucleus spin flip or electron spin flip? In other words, since every ...
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1answer
82 views

Non resonant modes in cavity

I have a simple question. Suppose we have a laser with a cavity such that the frequency of the light that the laser emits does not match with any longitudinal modes allowed by the cavity. In ...
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0answers
24 views

Frequency resonance of Bones, and other parts of the human body [duplicate]

Today in class we were learning about states of matter. I found out that in a solid the atoms are vibrating. This caused me to think about how crystal glass will break if an opera singer sings high ...
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20 views

Why does the 180°-pulse in mrt not sync all phases like the 90°-pulse does?

As far as i understand, in mrt with the constant field B0 pointing in the z-direction, the 90°-pulse "screws" some of the relaxed spins, so that the expectation value of their magnetic moment rotates ...
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1answer
108 views

Can gravitational waves resonate?

Can gravitational waves resonate? - Perhaps by creating standing wave interference in a cavity? Could that feasibly happen either in nature or by engineering?
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3answers
5k views

What is the resonant frequency of liquid water?

I learned it's not 2.45 GHz. But what is it, then? In my failure to find the real value, I'm starting to wonder: does it even make sense talking about a resonant frequency of water molecules?
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0answers
125 views

Stability of Mathieu's equation and parameteric resonance

I am given the following equation (Mathieu's equation) in my subject of Numerical Analysis : $$ \frac{d^2 x}{dt^2}=-\omega^2(1+\epsilon\cos(t))x $$ I am supposed to find those frequencies $\omega$ ...
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3answers
634 views

Definition of a normal mode?

What is the formal definition of a normal mode for a string? And how does this relate to the definition from e.g. wiki that seem to be applied to discrete systmes of particles only? Also on a string ...
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2answers
1k views

Why do objects have resonance at natural frequency?

What actually is a natural frequency for an object and what makes it vibrate with increased amplitude when coupled with an external oscillator that matches the natural frequency?
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0answers
32 views

What is the limit of directly detecting a resonance?

Some resonances are extremely short-lived. With a lifetime of $10^{-23}$ seconds, they would travel just about the size of the proton ($10^{-15}$ m) even if they traveled at the speed of ...
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2answers
412 views

Natural Frequency of an object and the phenomenon of resonance!

I have read about the term natural frequency in quite a lot of places. But I haven't found an explanation as to what is vibrating. It was pretty awkward when I couldn't clearly answer my little sister ...
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1answer
297 views

The Solar System explosion in the Nice model

This video depicts one variant of the Nice model (pronounced "neese", like the city in France). I'll briefly describe it in case the link ever dies. Here is the initial configuration: The four ...
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1answer
338 views

Forced Oscillations & Resonance

I need a very much physical explanation for the phenomenon of Resonance associated with forced oscillations (damped). I have gone through HRW and Concepts of Physics by H C Verma, but that wasn't of ...
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1answer
685 views

Why do I hear a deep rumble when I cover my ears?

Probably a trivial thing but a simple google search didn't show anything relevant about it. If I cover both of my ears with my hands, I hear a very deep rumble. If I slowly move my hands away the ...
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1answer
58 views

Why is permittivity or permittivity negative in certain metamaterials?

I read some papers and I think the explanation is that the driving electric (magnetic) field leads the response by π, thus making the effective permittivity (permeability) negative. But my question ...
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2answers
330 views

Why can we produce a sound by blowing across a blade of grass, a paper strip or similar

I just don't know how is the sound produced? Does it come from the vibration of the blade of grass or the air in the up and down?
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0answers
17 views

Does the mediation of electric or magnetic force require distinct electron orbitals?

In the case of ordinary photons of light, matter interacts with light via electrons that orbit the nucleus. If the specific energy of a photon E = hv can be found in the atom as the energy difference ...
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1answer
193 views

How does resonance store vibrational energy?

In the wiki article, it is written that in resonance, maximum amplitude is possible as vibrational energy is stored. What does that statement mean? How is energy stored so that max. amplitude ...
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2answers
91 views

Capacitor/Inductor Resonance

I am struggling to understand the concept on resonance in electric circuits. I understand that a inductor builds up a charge on it, then the current flows to the capacitor, charging it. But then ...
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1answer
436 views

How do you define the resonance frequency of a forced damped oscillator?

Consider a forced, damped harmonic oscillator $$\ddot{\phi} + 2\beta \dot{\phi} + \omega_0^2 \phi = j(t) \, .$$ If I pick a sinusoidal driving force $j(t) = A \cos(\Omega t)$, I find $$\phi(t) = ...
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0answers
41 views

What are resonant tori?

What is the definition of a resonant/invariant torus (in the phase space of a Hamiltonian system)? Are there non-resonant tori?