Questions tagged [resonance]
Resonance is a characteristic of physical systems having a structure that allows energy to flow between various states at a specific, oscillatory rate (resonant frequency). For a stable resonant system at steady state the internal energy is either fixed without losses or the rate of energy input is equal to the energy losses.
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How big can a current resonance possibly get and what are the sources of power loss?
A damped spring coupled to a sinusoidal force follows the differential equation
$$\ddot{x}+2\beta\dot{x}+\omega_0^2 x = f\cos\omega t .$$
It's well known that the amplitude of the spring in the ...
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What really is natural frequency and resonance?
Shouldn’t the frequency of an object depend on how much I push it from one end if the other end is attached?
And what’s resonance? In my textbook there is no such explanation to what is actually is ...
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Question on 1D Scattering Resonances
I'm reading Henley and Garcia's Subatomic Physics. To introduce the concept of resonances they use a 1D square well scattering example. Resonances are where the transmission coefficient goes to one.
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How exactly does a seashell make the humming sound?
My little brother asked me where the ocean-like sounds came from inside of a sea shell. I told him that the air trapped inside the shell vibrates, making a sound. But then he asked me why the air had ...
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Why do we get overtones in a high-overtone bulk acoustic (HBAR) resonator?
In HBAR we tend to observe a base resonant frequency and then overtones at higher frequencies. Why can't we have just one standing waves in between the top and bottom electrode? What causes the ...
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How does acoustic transducers have multiple resonances?
I am working with determining the variation of impedance of acoustic transducer with frequency. Below is the Van Dyke equivalent model of the transducer.
By analyzing this transducer equivalent model ...
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Resonating string with increasing amplitude
The situation goes like this: We have a tuning fork at one end of a string (whose other end is fixed to a wall and length $L$). The fork is vibrating with small amplitude so we approximate this end of ...
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Is there a generalization of mode coupling theory?
I am currently reading a lecture on coupled-modes theory and have a question regarding the ansatz:
$$E_\text{tot}=A(z)E_1(x,y,z) + B(z)E_2(x,y,z) \\ H_\text{tot}=A(z)H_1(x,y,z) + B(z)H_2(x,y,z)$$
and
$...
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How does a guitar string produce sound?
I'm curious about the mechanism of a guitar producing sound. Of course, I know once a string is plucked it vibrates in a superposition of several harmonics, but what I don't know is what happens next. ...
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Wave Experiment Method
Hello I am conducting an experiment to see how the tension, given by a hanging mass, affects the resonant frequency of a string. I would like to conduct 3 trials at 5 different tension forces/weights.
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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 ...
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Describing two levels of a spin 1 triplet with zero field splitting as an effective spin 1/2
I am working with NV centers and there one can describe the groundstate triplet of the system with a Hamiltonian of the form:
\begin{equation}
H_e = D \hat{S_z}^2 + g \mu_B ( B_x \hat{S_x} + B_y \hat{...
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Calculating the resonance frequency of a spring based on adding additional mass
I have a following problem. I have a spring of unknown spring constant and resonance frequency. I can measure only the force on the spring and the change in length of the spring. I can add mass and ...
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Has anyone calculated musical patterns of the planetary cycles?
Using a modern, logarithmic form for our musical scales, include the major planets, plus Ceres. Pluto and Eris for a wide coverage of our solar system, or any others you wish. Use the NASA Planetary ...
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Sound radiated by wind instrument
My understanding of how a wind instrument (modeled as a tube open on both ends) works is as follows:
Person blows into one of the open ends to create pressure waves.
These pressure waves are ...
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Resonant frequency of multi diameter closed pipe
I'm trying to make sense of how resonances in pipes work.
I gather that, in the instance below, the fundamental resonant frequency of the 1m closed pipe (ignoring end correction etc.) is
$$ f_{0} = \...
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Validity of approach to nonlinear, driven, damped oscillation amplitudes in L&L
In §29 of L&L mechanics, the authors discuss an approach to estimate the resonance amplitude of the equation
$\ddot{x}+2\lambda\dot{x}+\omega_0^2x = \frac{f}{m}\cos(\gamma t)-\alpha x^2-\beta x^3$ ...
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Is this image on harmonics and overtones wrong?
I saw this image and believed this to be the definition of what the relationship between harmonics and overtones to be in strings, closed pipes and open pipes.
That the $n^{th}$ harmonic = $n-1^{th}$ ...
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Memristor Differential Equation Help
I'm currently trying to solve the DE that defines charge in a circuit containing an Inductor, Capacitor, Resistor and (crucially) a Memristor. This needs to be able to work for any variable values and ...
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Ultrasonic whistling
My friend from physics who doesn't know whistling says he is good at whistling, but the resonant frequencies are ultrasonic so others cannot hear it.
Could this be right, or is he just bluffing?
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What duration of a white noise burst is required for it to be "white" at a given frequency or frequency range?
I am running white noise bursts (with very short ramps on/off to prevent discontinuities) through underdamped resonant bandpasses which are tuned to any given $f_0$ and an underdamped $Q$.
Continuous ...
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Questions about derivation of Fano resonance
In Fano's original paper about Fano resonance [https://doi.org/10.1103/PhysRev.124.1866], starting from equation (3b)
$$V_{E'}a+E'b_{E'}=Eb_{E'}\tag{3b}$$
one gets an expression for $b_{E'}$
$$b_{E'}=\...
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Is natural frequency a local or global property?
Some objects have a natural frequency. This can be anything from a metal ball to a table, etc. When we hit such an object, it will start vibrating with a certain frequency $f$. Because of damping the ...
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Statistics on Cauchy Distributed Data
So the Cauchy/Lorentz distribution is often used to describe distributions in physics (e.g. resonance). But theoretically, the Cauchy/Lorentz Distribution does not have a defined mean and variance, ...
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Should natural frequency be modeled using molecules?
Consider an object. This can be anything from a metal ball to a table, etc. Now this object has a natural frequency. When we hit the object, it will start vibrating with a certain frequency $f$. ...
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How is a resonant bandpass filter similar/different from a damped mass-spring oscillator? They seem to behave both similar and different in testing
Background
I am using resonant bandpass filters as musical oscillators. One can excite an array of them at harmonic frequencies and given Q values for a note by, for example, running a burst of noise ...
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Modeling a viscoelastic string with a collection of damped spring oscillators? (To replace finite difference model.) How to find $Q$ per harmonic?
Background
I have simulated a vibrating viscoelastic string fixed at each end under tension using finite difference modeling. Most simply this can be done using Kelvin-Voigt style mass-spring dampers ...
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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 ...
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Why sharp resonance corresponds to a particle?
First picture below is from last section of 23th chapter of Feynman's Lectures on physics. I don't understand the red line.
This section talks about resonance in nature. It was very interesting and I ...
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Why actually at resonance the inductive and capacitive reactance cancel each other?
I am learning about series LC circuit that is in resonance. It says it is when the impedance offered is minimum due to the angular frequency being at a particular value(1/√LC).People say that they are ...
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Frequency Response of a Stochastic Oscillator Numerically
I am willing to obtain a frequency response plot for a stochastic oscillator governed by the following equation numerically.
$$
\ddot{x}+2\Gamma \dot{x}+\omega_{0}^{2}x=f(t)
$$
where $f(t)$ is a ...
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Are transitions from a broad quantum state to itself possible?
If you have a broad quantum state (e.g. a nuclear resonance) and you populate that resonance at the high energy end - is it quantum mechanically possible for the state to decay "into itself",...
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How can one explain the small amplitude resonance before the onset of main resonance condition?
I was using a sonometer to verify the frequency of a.c. supply in the lab is 50 Hz. For this the equation I used is
f=(1/4L) x Sq. root (T/m)
I set tension T = 4.9 N by hanging 0.5kg mass
mass per ...
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Air Columns non-resonant frequencies
I understand that both open and closed-end air columns have many resonant frequencies, called harmonics and a fundamental frequency. At these frequencies, we expect to observe standing waves of ...
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Force-dependency of frequency response of driven harmonic oscillator with damping
For a driven harmonic oscillator with damping of the form
\begin{equation}
\ddot{x} + 2\xi\omega_0\dot{x} + \omega_0^2x = \frac{F_0}{m}cos(wt)
\end{equation}
with damping ratio $\xi$ and natural ...
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Resonance of a non-straight pipe
Simple question, but I can't find any answer around.
If a pipe turns, aka is not straight, the length of the pipe (in order to calculate the resonance frequency) is given by the length of the ...
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General solution for Parametric amplification in harmonic oscillator
It is well known that for the simple harmonic oscillator of the form
$$
\frac{d^{2}x}{dt^{2}} = -\omega_{s}^{2}x
$$
where $\omega_{s}$ is the resonant frequency of the oscillation, has the general ...
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Loss of energy during harmonic resonance
I have been trying to determine the function describing how energy is lost during harmonic resonance:
Say an input of energy at the resonant frequency of a closed resonator. I know the following ...
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Why do you feel ripples by sliding finger on an AC-powered macbook surface?
It doesn't have to be a MacBook exactly, other switched power supply powered metal case devices are good enough, but MacBook is the most common.
It must be AC powered; the effect disappears when ...
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Why can $Q$ be calculated by $f_0/f_{FWHM}$?
I found this expression for the reflection signal of a microwave cavity:
$$
|\Gamma|^2(f) = 1-\frac{1-\Delta M}{\left(2Q\left(\frac{f}{f_0}-1\right)\right)^2+1},
$$
with $f$ the frequency, $f_0$ the ...
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What is the allowed wavelength range over which the Fabry Perot intensity pattern is formed?
I'm working with a Fabry Perot cavity with a length of 55 mm and an incident wavelength of 1550 nm. From theory the FSR of the FP cavity can be either computed using the equation
FSR = λ^2 / (2 n L)
...
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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 ...
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Non-resonant source in a conducting cavity, what happens?
First of all I'm aware of this post but my question is a little different.
Say we have a perfectly conducting cavity with supported frequencies $\omega_n$ and a harmonically varying source within ...
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What exactly are resonances in particle physics?
I am very confused about this, are they an excited state of a particle where an electron is excited to an upper energy level, which seems less likely to be the case since the resonant states of ...
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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 ...
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Fourier Transform of Damped Oscillations - Zero Frequency Peak and Shift [duplicate]
A damped oscillator has the time evolution:
$$ y(t) = e^{-\Gamma t}\cos^2(\tilde{\omega}_0 t)$$
where $\Gamma$ is the damping rate, $\tilde{\omega}_0^2=\omega_0^2-\Gamma^2$ and $\omega_0$ is the ...
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Harmonics in closed and open pipes
What exactly would happen if we sent a frequency that was not one of
the harmonics into a closed and open pipe? What would happen if we
gradually increased this frequency?
From my understanding, I ...
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Perturbations of an integrable system with no resonant tori
Suppose I have a Hamiltonian $H_0$ which is just a collection of $N$ non-interacting harmonic oscillators. Written in action-angle coordinates $(J_i, \theta_i)$ we have $H_0 = \sum_{i=1}^N \omega_i ...
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How does a violin produce notes, microscopically?
I believe this question would have been asked before, but not like this. The popular answer to this question is that the slide-release action of a bow sets up vibrations in the strings, of which ...
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Why is there a pressure node at the open end?
The pressure at the open end is equal to that of the atmospheric pressure. So how can it be a pressure node when the pressure is not 0? It is the atmospheric pressure.
Edit: Is there an intuitive ...
