# Tagged Questions

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

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### Is it possible to determine maximum frequency of a disc using a relative circumference?

On Wikipedia there is an article that shows how to calculate the relativistic effects on a rigid spinning disc, I am referencing the formula under the "Ehrenfest's argument" section in the link. The ...
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### Math formula for crystal glass resonance [duplicate]

For a music therapy experiment, I have to use several crystal glasses with water and different cylindrical shapes, and make them vibrate and produce different sounds. Is there a math formula that ...
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### Frequency of an electron

If frequency is defined as the cycles per time, then what is meant by "frequency of an electron"? If it refers to the rotation of electron around a nucleus, then which phenomenon is considered for a ...
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### What experimental evidence shows that sound velocity is the same for all wavelengths?

I'm studying sound waves with Halliday's book, and after reading the whole chapter, one of the questions suggested was: What is the experimental evidence that allows the assumption that the sound ...
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### Manufacturing Fresnel Lenses with Sound

I understand fresnel lenses are manufactured using CNC machines. I was wondering, if it would be possible to use sound to vibrate liquid silicon and then fast cool it into the standard form of a ...
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### Can frequency be equal to 0?

Is correct to speak about frequency equal to 0 ? $$f= \frac{1}{t}$$ If $t\rightarrow\infty$ can I consider that the frequency is equal to 0 ?
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### What is the history behind the factors of 3 in the classification of electromagnetic radiation?

What is the history behind the factors of 3 in the classification of electromagnetic radiation? See e.g. http://en.wikipedia.org/wiki/Radio_spectrum#By_frequency Is this (just) inherited from the ...
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### How to capture electomagnetic radiation/waves?

If I wanted to find out what kind of electomagnetic waves "travel" through my room at which frequency, what kind of equipment would I need? Suppose I want to view frequencies from 0 Hz to 6 GHz.
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### Why does the frequency of a wave pulse on a string only depend on the source of the wave pulse?

I am reading wave pulse on a string and their reflection/transmission, and my book says that frequency of the pulse depends only on the source of the wave pulse. But I am unable to understand why is ...
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Apart from physics, I love music and I want to learn about musical acoustics. I know some things, but the problem is that most of musical acoustics books are written for musicians. That means that ...
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### Can sound frequency create more ideal conditions for fire?

You may have seen the recent story of a device that engineers claim can extinguish flames using sound frequency. An older article loosely explains the theory behind how this works: Sound travels ...
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### Frequency of Light Near a Massive Object

We know that near a massive object, light's wavelength and frequency changes, but its speed remains same. I'd like to know how it is possible for frequency to change, unless we change the light ...
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### How does one measure the frequency of a laser?

I am taking a short introduction course on lasers. I never knew that the frequency of a laser is so high for a given wavelength (e.g. 780nm). I am wondering how people can measure the frequency of the ...
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### Frequency Modulation

If FM radios work by modulating the frequency, how is it that we can tune into a specific channel, and hear a song or station? Wouldn't the channel need to be modulated along with the varying ...
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### Resonance and natural vibrations in vacuum

In my Physics textbook, it says that if two pendulums of the same natural frequency are placed next to each other and if one is set into vibration, the other starts resonating and when the first one ...
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### How does energy depend on frequency in an alternating current circuit?

In what relation is the energy input in an alternating current circuit to its frequency? I'd guess I have to compute something like $$E=\int P(\omega,t) dt=\int U(\omega,t) I(\omega,t) dt,$$ but ...
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### Angular frequency. Wrong interpretation at Wikipedia?

This and this articles mention that the angular frequency is: number of oscillations per unit of time But this doesn't seem to be correct since the angular ...
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### Period on the phase plane (small oscillations)

I have this formula to calculate the period of a motion in the phase space (plan, in this case) along a phase curve. $$T(E)=\int_{x_1}^{x_2}\frac{dx}{\sqrt{2(E-U(x))}}$$ ...
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### How to find the first-harmonic frequency from the frequency spectrum of a recording of this harmonic being struck on a guitar?

Just as the title implies, I was trying to find the fundamental frequency of a guitar string at various tensions as a part of an experiment to find its Young's modulus. In the experiment, I connected ...
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### What is the most common photon wavelength in our observable universe (not including the Sun)?

Ignoring the Sun, what is the most common wavelength of a photon that is received by us on average? (I am not asking what is the average wavelength, but rather what is the most common wavelength ...
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### 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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### Why does the period/frequency of a fan slow down significantly when I taped a piece of rubber band to it?

All of this was done with a standing fan set horizontally on a table. During an experiment, I had to tape a piece of rubber band to one of the standing fan's blade and measured the period of the fan. ...
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### Are there any ways to alter frequency of wave?

I want to know how can we change frequency of wave, both sound and light, and what is the nature of "changing frequency" Such as, any material could absorb and re-emit wave in another wavelength. Or ...
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### What does it mean by complex frequencies? (Quasinormal Modes)

Something I've taken for granted and not yet thought about physically, is how the frequency of quasinormal modes related to a black hole are $\textit{complex}$. I know that it's something to do with ...
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### How to calculate Standing Waves in Electrical Cables?

I have a 20 metre Coaxial Cable. I send digital signals down the cable ranging from 5 KHz to 50 KHz. I have noticed a pattern in the noise ratio, an oscillating wave. I predict this is to do with ...
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### Frequency Response RLC circuit - Current against Frequency graph - Symmetry?

I understand that in a Frequency Response experiment dealing with an RLC circuit, the graph of Current against Frequency is supposed to be symmetrical about the resonant frequency theoretically. ...
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### How do the energy eigenvalues of rotational degrees of freedom in statistical mechanics come about?

I want to understand the hierarchy different degrees of freedom of a mechanical system. Specifically, I want to understand which subsystems equibrilate faster and why. This question comes up: Why ...
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### Doppler shift for a uniformly accelerating observer

This was given in textbook as an example. An observer on a spaceship with a four velocity $u$ is approaching from $x = +\infty$ a star at rest in the reference frame $S$ while undergoing constant ...
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### Color in Different media

When a light wave passes from one medium to other, the wavelength of the light wave changes and the frequency remains constant. If then color of the light waves depends on changing wavelength or ...
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### Red color has largest wavelenght and violet minimum (in the range of visible light). then why does violet light appears reddish? RED + BLUE = VIOLET [duplicate]

My question is simple. Green light is more similar to red light than violet, then why is violet reddish and green not? in the language of frequencies and wavelengths, red and violet should contrast ...
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### Can someone please explain the “infrared catastrophe”?

In my readings I've run into this idea of an "infrared catastrophe" associated with 1/f noise. As far as I can tell it is because when you graph the periodogram of the 1/f signal you see the PSD goes ...
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### Relation of color and frequency for the visible spectrum

In this question the OP is looking for a way to see light that is outside of the visible spectrum without using electronic sensors. This got me wondering about the visible spectrum itself. Typically ...
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### Is energy always proportional to frequency?

Google has no results found for "energy not proportional to frequency" and many results for E=hf. Is there an example of an energy that is not proportional to frequency?
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### How would natural (resonant) frequencies affect amplitudes?

I read $y=A\sin(2\pi ft)$, where $A$=Amplitude, $f$=Frequency, $t$=Time and $y$=$Y$ position of the wave. Since natural frequencies only take the most effect when they are close to the frequency. How ...
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### Do we see color with higher frequency first?

Out of the 7 colours of the rainbow, violet has the highest frequency and the smallest wavelength. Does this mean that our eye sees it first? If yes, then why? Does it travel at the same or higher ...