Questions tagged [frequency]

Frequency is the rate of repetitive aspect in the amplitude over a given dimension.

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Converting a turbulence spectrum in frequency to wavelength

So, I have a spectrum calculated from an underwater sensor, $S_{vv}(f)$, and want to convert it to $S_{vv}'(k)$, where $k$ is wavelength and $f$ frequency. I assume Taylor hypothesis for frozen ...
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Low hum from nowhere or everywhere? [closed]

I've heard reports from all over the world about a low hum at various parts of the day and night.  Could air conditioners and other automated machinery, hum of power lines be the culprit? When we see ...
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Defying gravity with vertical shaking? [closed]

I saw this video on levitating a denser liquid on less dense air by vertical shaking. But I couldn't understand some points in the video. 1 : How did the liquid levitate ? I think it's because of ...
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Is gravitational Force is damping force in vertical mass-spring system of constant k in Simple Harmonic motion

When a block of mass m is suspended by vertical spring system,it for sure perform SHM in the absence of damping force,only force which act on the system is internal which is -kx, where k is spring ...
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What is the differnce of angular velocity and angular frequency in angular SHM

A body free to rotate about a given axis can make angular oscillation. This angular oscillation are called Angular simple harmonic motion, In derivation, Ohm = theta ✖ w ✖ cos(wt+ phi) Where omega is ...
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Do gravitational lenses act as prisms?

Light creates gravity, and the greater the light's frequency, the greater this gravitational effect is. It stands to reason then that light of different colors would react slightly differently to ...
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Intuition behind forced oscillations

in every book I own and on the internet, any information on forced oscillations is a version of the following definition, followed by the solution to a differential equation. Forced oscillations: ...
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How do I describe the following system? [closed]

So the professor of my physics 3 class assigned this problem regarding forced oscillations. A mass of 0.30kg hangs of a massless rope. The center of oscillation can move as shown in the figure. When ...
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What does frequency mean in the transition energy of electrons?

I have read many questions on this site about how do transitions occur? What happens during transition? The answers are extremely good but I have a doubt. What I couldn't understand is why is ...
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What does determine the frequency of gravitational waves caused by inflation?

It is theorized that during inflation gravitational waves are produced. See this article by Guzzetti, Bartolo, Liguori, and Matarrese (Cornell University). Or this one by Liu, Guo, Cai, and Shiu (...
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Confusion about the relation between Einstein $A$ and $B$ coefficients

In hyperphysics website it's shown $$\frac{A}{B} = 8πh\frac{\nu^3}{c^3}.$$ But in many famous textbook like Quantum Mechanics: Concepts and Applications Textbook by Nouredine Zettili the formula is ...
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Frequency of Tuning Fork

Does the frequency of a tuning fork depend on the strength by which it is struck? If yes, then how was the actual frequency(stated on the tuning fork) calculated? Was there a defined or average human ...
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What does the disconuity in the equation for modulated phase mean when superposing two SHM?

So I was working out the result of the composition of two SHM that are in the same direction and have different frequencies and amplitudes. Turns out I found the following equation for the modulated ...
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Intuitive explanation of Nyquist rate?

Is there an intuitive way to understand Nyquist rate (i.e., that, in order to prevent loss, an analog signal must be digitized at a rate twice as high as the highest frequency component of the signal)....
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Half sphere in waveguide

So, the cutoff freq, $f_c$ of a rectangular waveguide is following: $$f_{c}=\frac{1}{2\pi\sqrt{\mu \epsilon }}\sqrt{(\frac{\pi}{a})^{2}}.$$ For TE10 mode, the equation is a little weird as I am ...
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Derivation of angular frequency of underdamped harmonic oscillator [closed]

Why is the angular frequency of an underdamped harmonic oscillator given by:$$\omega_1=\omega_0\sqrt{1-\zeta^2}$$
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Is the pulsar frequency measured by light the neutron star rotation frequency?

Reading some papers about NS found some astronomers measured frecuency of a pulsar. My question is if that quantity is the same as the frequency of rotation of that star (J).
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Does this experiment VIOLATE Einstein's theory of photoelectric effect? [closed]

We will use another light source of exactly the same frequency and emitting area in this experiment as shown in figure The distance of both the sources is adjusted to be the same indicated as d and ...
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Frequency and intensity in photoelectric effect

In the explanation of photoelectric effect it is written that intensity and frequency of radiation have different results i.e. higher intensity means greater number of emitted photoelectrons and ...
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Can l apply force using light wave? [duplicate]

Can I make light dig a hole by increasing it's frequency? Can I relate force with wave using the equation $c=$ wavelength$\times$frequency?
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Which fact is true about the speed and frequency of light?

I am totally stuck over this concept and google doesn't help. First, We say that light's speed is constant for all colors in vacuum but different in all other media. Then which color's speed are we ...
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Does intensity of light waves also depend on frequency or only on square of amplitude? [closed]

Two light waves travelling in same medium are given by $$E_1 = 2\sin(100πt – kx + 30°)$$ and $$E_2 = 3\cos (200πt – k'x + 60°)$$ The ratio of the intensity of the first wave to that of the second wave ...
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Do all sounds that have a pitch have a fundamental frequency?

My current understanding is that if a sound has a pitch it must be periodic, i.e. it is composed of sound waves that have frequencies. So I assume that means there must be a fundamental frequency. ...
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How does an object with overtones vibrate?

Suppose we have a tuning fork, we know it will vibrate at a constant pitch(frequency). Let's say the tuning fork is of 440hz, so I imagine the prongs of the fork to be vibrating 440 times per second, ...
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Are there any materials transparent to $\gamma$-rays, and to which frequencies an ordinary glass is opaque?

I know that materials are generally opaque to frequencies of light that matches their own natural frequencies. I wonder if there are materials transparent to gamma-waves. That is, high fluxes of gamma ...
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Can a sound wave have such high frequency that it causes permanent displacement of medium?

Is it possible to have a sound wave with frequency so high that it causes permanent displacement of matter (the frequency is greater than the elasticity of the medium, so the medium is unable to ...
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Where does the minus sign go when deriving the Stefan-Boltzmann Constant?

When deriving the stefan boltzmann law from planks law. You may make a substitution (http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan2.html). This substitution will lead to a stray minus sign ...
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Why is the transmission data rate between Mars and Earth so low?

I read that we get between 500 and 32k bits per second when sending data from Mars to Earth. Apparently it's substantially higher between Moon and Earth. What are the reasons? Please explain the ...
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What is “spectral turnover”?

In a paper which deals with the spectra of radio frequency cosmic events, the word “spectral turnover” is used. What is “spectral turnover”?
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Comparing a 100W and a 40W light bulb that only emits a specfic frequency

I'm sort of confused by this... let's just say the bulbs only emits green light, and we compare a 40 W and 100 W bulb (identical except one is brighter than the other), since the frequency of light ...
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Frequency of signal means changing or moving?

I saw some where frequncy means how fast a signal is changing and i am confused. Since frequncy means how much cycle a signal completes in unit of time and we may say how fast a signal is moving but ...
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Intuitive Explanation for Doppler effect?

I was looking for an intuitive explanation as to why the Doppler effect happens. I haven't found any, but this is what I thought: -Waves emitted travel at a constant speed -The source emits a wave -If ...
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Why does higher frequency sound dampen faster in air?

I know as a general fact that higher frequency sound dampens quicker in air so when music is heard from a distance only the bass part is audible.But I don't know what the physical reasoning behind ...
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Confusion on the indice of refraction: is it dependent on the frequency or not? [duplicate]

I saw in my course than when light hit a medium, it makes some dipole oscillating with the same frequency as the one of the light $\omega$. By a classical mechanics reasoning, one can show that the ...
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formula to know when 3 sine waves with different frequencies reach first point together again? [closed]

I'm looking for formula if any or shortcut math, for following problem. Let's say we have 3 sine waves with frequency 100, 70, 20. Assuming all 3 start on point-0, each wave cycles based on it's own ...
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How can we explain the broad features of this guitar spectrogram?

This is inspired by this music.SE question, which I attempted to offer an answer for, but the more I think about it I am still quite unsure about it. As physicists, we often try to describe features ...
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What’s the difference between ‘decimated‘ and ‘undecimated’ data?

How is ‘decimated’ data different from ‘undecimated’ data?
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Off-diagonal terms of a frequency response matrix

If I have coupled system of two harmonic oscillators. $$\ddot{x}_1+\Gamma\dot{x}_1+kx_1-kx_2=0$$ $$\ddot{x}_2+\Gamma\dot{x}_2+kx_2-kx_1=0.$$ Then I can fourier transform the equations of motion and ...
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Resonance frequency with metal

I've made an experiment with resonance frequency of a LC circuit. One part was to place a metal (I think iron) in the middle of the induktivity of LC circuit. I measured a higher resonance frequncy as ...
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How is the frequency of a wave defined if it propagates on three different directions?

Let's consider a wave which propagates on 2 or three directions, like for instance an electromagnetic wave inside a rectangular waveguide totally closed on two ideal conductor surfaces: The walls of ...
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What is the energy spectrum of all photons in the observable universe?

Does anyone know what the energy spectrum for the entire universe looks like? In other words, what would the graph look like if you plotted the number of photons on the $y$-axis and frequency on the $...
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Why is my experimental inductive reactance not directly proportional to frequency [closed]

For a lab report, I am measuring the voltage across a 300 mH coil when connected to an alternating current supply at different frequencies. From this, I want to graph the inductive reactance (...
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How do I get $\omega$ in de Broglie’s formula?

Suppose I have the ground state $\psi$ of some Hamiltonian $H$ and I want to get energy eigenvalue of $\psi$ without doing $H \psi = E \psi$. De Broglie’s formula $$ E = \hbar \omega, $$says I can get ...
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Why can we equate these two integrals related to blackbody radiation?

I was reading this Wikipedia article which describes how Planck’s Law of blackbody radiation is derived. Letting $B(v,T)$ represent the energy emitted at frequency $v$ and temperature $T$, the article ...
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How does the Brownian motion of air molecules compare to the threshold of human hearing as a function of frequency?

This fantastic question essentially asks what is the noise floor of air? Both the answer given on that thread and the value stated by Microsoft are around -23 or -24 dBSPL. However, overall loudness ...
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Quality factor definition

During my study of oscillators I have encountered two different ways do define the Quality factor $Q$, which gives information about the amount of damping on a system. Suppose the oscillator equation ...
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Neutrino oscillations

It seems well documented that neutrinos oscillate between flavours. In the link there are some figures which show probabilities but it isn't clear to me why the abscissa is measured in $L/E$. Is it ...
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Why does frequency of a wave depend solely on its wavelength?

On Wikipedia it was stated that a wave's speed $v$, wavelength $\lambda$ and frequency $f$ are related by the identity $$v(\lambda)=\lambda f(\lambda).$$ The function $f(\lambda)$ tells us that the ...
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What is the meaning of the angular frequency of a spring?

In this differential equation, $$ \ddot{x} + \frac{k}{m}x = 0 $$ We assume that $$ \frac{k}{m} = w^{2}$$ Why is that? And how one can prove it?
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If frequency is continuous shouldn’t energy be non-quantised?

If $E=hf$ and the frequency of electromagnetic waves is continuous (i.e. you can have frequencies of $1.5\ Hz$ or $0.3\ Hz$ for example) then surely energy isn’t discrete or quantized into because one ...

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