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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108
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7answers
21k views

Why do tuning forks have two prongs?

I believe the purpose of a tuning fork is to produce a single pure frequency of vibration. How do two coupled vibrating prongs isolate a single frequency? Is it possible to produce the same effect ...
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2answers
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Why does our voice sound different on inhaling helium?

This question (and answer) is an attempt to clear the air on what appears to be a very simple issue, with conflicting or unclear explanations on the internet. Arguments, negations, etc are invited. I'...
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Why is Microwaved mac & cheese burnt where they touch?

After reheating cold about 1.5 oz. of Annie's Mac & Cheese shells for 15 seconds on high power in the microwave, the mac & cheese was burnt black only at certain points where the pasta is ...
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5answers
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Why does pitch increase when you blow harder into a whistle?

When you play recorder or whistle, the pitch depends on how hard you blow into the tube. E.g. when you blow a whistle, initially the pitch is slightly lower when there is less air flow. This seems ...
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10answers
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Why do string instruments need hollow bodies?

My textbook states, 'The sound box has a large area, it sets a large volume of air into vibration, the frequency of which is same as that of the string. So due to resonance a loud sound is produced.' ...
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9answers
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Intuitively, what actually is the cause of resonance?

Please don't explain it mathematically. I have been searching for the reason for a long time. I have watched Walter Lewin's video giving an example of resonance, but I didn't get the reason behind the ...
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3answers
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Theory behind patterns formed on Chladni plates?

In this video of vibrating Chladni plates we can see small sand particles align themselves into different interesting patterns (also shown in the image below) which correspond to some particular ...
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Non-resonant but efficient frequencies

I understand that if the frequency of a driving force coincides with the natural frequency of an oscillator (say a pendulum), the rate at which energy is transferred to the same is maximized. However, ...
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1answer
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Why don't tuning forks have three prongs?

I was reading Why tuning forks have two prongs?. The top answer said the reason was to reduce oscillation through the hand holding the other prong. So if having 2 prongs will reduce oscillation loss, ...
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6answers
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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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Resonances in high energy physics

I still do not understand what a resonance precisely is. Is it exactly the same as a particle? Or only an excited state? And why does it make a peak in some diagrams? And which diagrams?
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1answer
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Why does an acoustic guitar body amplify all notes and not just certain ones?

We all heard that acoustic guitar body acts as the amplifier of the sound created by wire plucking and strumming. This is because an acoustic guitar body is some kind of resonator. Every resonator ...
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Definition of the $Q$ factor?

According to Wikipedia, the $Q$ factor is defined as: $$Q=2\pi\frac{\mathrm{energy \, \, stored}}{\mathrm{energy \, \,dissipated \, \, per \, \, cycle}}.$$ Here are my questions: Does the energy ...
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Is the length of the day increasing?

In Frontiers of Astronomy, Fred Hoyle advanced an idea from E.E.R.Holmberg that although the Earth's day was originally much shorter than it is now, and has lengthened owing to tidal friction, that ...
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Does the human body have a resonant frequency? If so, how strong is it?

Inspired by this question on Music beta SE, I'm wondering if the human body has a strong resonant frequency. I guess the fact that it's largely a bag of jelly would add a lot of damping to the system, ...
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Help me understand resonance

I don't fully understand how resonant chambers work. My confusion stems from the fact that the chambers are passive elements or filters, yet somehow are able to amplify the sound. Questions: How ...
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2answers
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Why, when one opens 1 car window, does that noise occur?

When you're driving and you open 1 car window, say the front one, there comes a horrible noise, but when you open another window just the slightest bit, this noise goes away (I'm sure most people know ...
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1answer
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Why do you only hear high frequencies when a microphone is near its speaker?

The phenomenon I'm talking about is positive feedback, as known from control engineering: when the microphone is too close to its speaker, it can "hear itself", so the signal will be infinitely ...
12
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2answers
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How do you define the resonance frequency of a forced damped oscillator?

Consider a forced, damped harmonic oscillator $$\ddot{\phi} + 2\beta \dot{\phi} + \omega_0^2 \phi = j(t) \, .\tag{1}$$ If I pick a sinusoidal driving force $j(t) = A \cos(\Omega t)$, I find $$\phi(...
12
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1answer
733 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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3answers
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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 ...
11
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2answers
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Understanding radiation and coupling of LC circuits

I'm trying to get a more intuitive understanding of resonant inductive coupling. It's supposed be a more efficient way to transfer electrical energy wirelessly, because the coils are only coupled by ...
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4answers
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How can standing waves be produced in an open organ pipe if the ends are open?

How can standing waves be produced in an open organ pipe even though both of its ends are open? Can someone explain with more clarity?
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What is a linear system?

I was reading about Resonant Frequency, and found a lot of information about it: like its uses in daily lives, for eg: swing, pendulum. etc I also read about its advantages and disadvantages but the ...
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5answers
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A conceptual doubt regarding Forced Oscillations and Resonance

While studying about the Resonance and Forced Oscillations, I came across a graph in my textbook that is given below:- Now, the author writes As the amount of damping increases, the peak shifts ...
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1answer
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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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4answers
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Phase difference of driving frequency and oscillating frequency

Suppose 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' oscillation frequency. However I'm told that the phase ...
8
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3answers
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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 $$\...
8
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1answer
350 views

How does a guitar work?

Here are four different possible ways: The plucked string vibrates longitudinally, vibrating the air around it. This vibrating air then causes the air inside the sound box to vibrate also, which ...
8
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3answers
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Why choosing for prime numbers eliminates vibration?

I have read that the spokes of a car wheel are usually five because, besides other substantial reasons, five being a prime number helps to reduce vibrations. The same also happens with the numbers of ...
8
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1answer
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$Q$ factor of parallel RLC circuit in series with a capacitor and resistor

I know that for parallel RLC circuits, the $Q$ factor is given by: $$ Q = R \sqrt {\frac{C}{L}} $$ But now suppose it is connected in series to a resistor $R_2$ and capacitor $C_2$. Would the $Q$ ...
8
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2answers
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Why does a container with fluid make different sounds at different fluid levels?

Have you ever noticed that when you are filling a container with fluid. As it approaches the top, it makes a different sound? You can tell by listening when your about to reach the top. Why is this?
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1answer
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Sound from cupping hands over ears

Sit in a silent place and then bring your hands close to your ears and cover your ears, you will start hearing some sound but if you remove your hands you don't hear it anymore. Can anyone explain ...
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1answer
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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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2answers
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Intuitive Cause for End Corrections

I have looked for an intuitive description for the reasons for end corrections. I find most of them with mathematics far beyond my level (high school). I found two sites that attempted to explain it, ...
8
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1answer
399 views

What is the waveform for a Rubens' tube driven slightly off-resonance?

This video has a nice description of resonance inside a Rubens' tube, and it has some pretty nice visuals of the tube being driven at the precise resonance, as well as just above resonance: I rather ...
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0answers
101 views

How is Mössbauer spectroscopy so resistant to thermal motion?

Mössbauer spectroscopy detects tiny shifts (on the order of $\rm{\mu eV}$ or $\rm{meV}$) in a gamma ray's energy due to the chemical environment of the nucleus. The scan consists of moving a source ...
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6answers
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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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3answers
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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 ...
7
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3answers
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Why are the closed and open ends of an organ pipe nodes and anti-nodes?

Here is a diagram of a wave in an organ pipe you'll find in most physics books Waves in air are longitudinal (not traversal), so what do the curves represent? Why are the open ends always anti nodes ...
7
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2answers
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Reflection of sound waves from the open end of an organ pipe & relationship b/w nodes & pressure [duplicate]

We know that standing waves are created when any wave traveling along the medium will reflect back when they reach the end. But in an open organ pipe, there is nothing to oppose the wave and reflect ...
7
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3answers
8k 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?
7
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2answers
122 views

Why coupled oscillators tend to seek integer frequency ratios?

In this document, the author writes (page 225) Coupled oscillators have a tendency to seek frequency ratios which can be expressed as rational numbers with small numerators and denominators. For ...
7
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1answer
246 views

Air oscillation at open window of a moving car

When driving a car with an open window one can hear (and feel) oscillations of air at the threshold of the open window. I used to think the open window and the car interior were forming a Helmholtz ...
6
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3answers
570 views

Forced Oscillation Explained with Violin String

In this lecture on Forced Oscillations, Normal Modes, Resonances, Musical Instruments, the professor says that by moving a bow over a violin string, you expose it to a lot of frequencies. Is there a ...
6
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2answers
2k 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 ...
6
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2answers
834 views

Longest ringing/resonating object [closed]

I am interested in objects which resonate or ring for as long as possible. In particular, I am interested in Crotales (https://en.wikipedia.org/wiki/Crotales), and if it is possible to make a longer ...
6
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3answers
211 views

Vibrating string as a dynamic system

It's known first order dynamical systems had one energy storage (example C, in RC circuits) these systems act as a filter but don't resonate, on the other hand a second order system had two energy-...
6
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2answers
659 views

About Nuclear magnetic resonance

I'm trying to understand the basic principles of Nuclear Magnetic Resonance reading this link but I have some doubts: 1) I have ever known that when protons aren't in a magnetic field, their spins ...
6
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1answer
418 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?

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