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

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Resultant frequency if 3 harmonic notes (a chord) is played

If I know the frequency of individual notes being played (let's assume D, F# and A), how do I determine the final frequency if they are played (nearly) simultaneously as a chord. To put the problem ...
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67 views

The Frequency of a Trill

My music teacher recently pointed out to me that, when performing a trill (alternating between two notes very quickly) the finger for the higher note should be placed slightly lower on the string than ...
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21 views

Interference of two waves of different frequencies relevance to background noise + sonometer

If two sound waves of different frequencies are recorded then does the interference between the two waves of different frequencies alter the resultant frequency recorded. In better context, I'm ...
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94 views

Resonate frequency of an object?

Below is a paragraph taken from the web site, physicsclassroom.com: It is often useful to think of these electrons as being attached to the atoms by springs. The electrons and their attached ...
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53 views

A simple question about frequencies, vibrations and engineering

I am a composer that likes science a lot but I am less than amateur at it. I am trying to start understanding how low frequencies (below 100hz let's say) behave. The intent is to find solutions to ...
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45 views

Audible frequency of an air vent increases with distance: what's going on?

I was just standing near a loud air vent that was roughly at eye level and pointing downward. I noticed something strange about the noise it was making - the further away from the vent I stood, the ...
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1answer
19 views

Why there are spikes in permittivity Vs. frequency curve?

When the frequency is increased the permittivity of a dielectric material decreases. But in the way of decrease there are some spikes which indicates sudden increase of permittivity for certain ...
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1answer
662 views

Spring system - 3 DoF system and its properties while changing stiffness

I was given the attached 3 degree of freedom spring system with the purpose of analyzing it. I came up with the following equation of motion and then I ran Matlab to calculate the corresponding ...
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1answer
52 views

Gravitational “acceleration” and frequency change of a photon?

For massive particles, force translates into acceleration which again is a change of the velocity vector in direction and/or magnitude. For a photon, the velocity magnitude cannot change, only the ...
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220 views

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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1answer
33 views

Fundamental frequency of a material and its Young's modulus

I wonder if there is a connection between fundamental frequency and Young's modulus of a material. For example, how to calculate the Young's modulus of a glass bar by knowing its frequency spectrum?
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1answer
96 views

Do Sidebands mean the frequency of an AM radio wave is not constant?

I'm studying for A-level now..... I have read some other posts explaining how the sidebands generated after the carrier wave is modulated. So, if there is sideband frequency, the frequency isn't ...
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1answer
21 views

How to compute $L_{\rm eq}$ from temporal pressure data

I have pressure vs time data. how can I compute sound equivalence Level $L_{\rm eq}$ in decibels? can this be done from a frequency spectrum assuming that it is constant?
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32 views

is it possible to change the energy of a waveform like radio wave & turn it into microwave?

In the electromagnetic spectrum, the differences between all waveforms are the "frequency" & energy of the waveform. We are able to modify both of these parameters. So, is it possible to change ...
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1answer
66 views

light color and refraction

I'm a bit confused on the topic of refraction, some starting premises: 1) When light refracts from exiting a medium with a low n and entering a medium with high n the light bends. 2) The index of ...
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36 views

Books about musical acoustics

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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44 views

Resolution of two frequencies

If I am trying to resolve two features in frequency space, with central frequencies A and B and a 'spread' (standard deviation, FWHM etc.) of $\sigma_A$ and $\sigma_B$ what is the spectral separation ...
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70 views

What is the highest frequency directly detected?

The Feynman Lectures of Physics states: In fact, although we mentioned many frequencies, no phenomenon directly involving a frequency has yet been detected above approximately $10^{12}$ cycles per ...
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76 views

De-excitation and vibrational frequency

By utilising energetic beams of particles it is possible to set atomic nuclei into vibration. For a certain nucleus the subsequent de-excitation results in the emission of photons of energy $1$ $MeV$. ...
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185 views

What is the maximum possible frequency and wavelength?

As a start I assumed Planck angular frequency which is the reciprocal of Planck time as the frequency upper limit, but not so sure. On the other hand, is there a lower limit? Can we consider the ...
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720 views

Chladni Plate Mathematics

I am a high school student doing an IB Extended Essay investigation concerning the resonant frequencies of Chladni plates of differing materials and sizes. Would someone please explain the definition ...
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57 views

Harmonics of an infinite cylinder

If a hypothetical cylinder was infinitely long, could it vibrate at any frequency, since any frequency would be a harmonic of it? And (less hypothetically) if a cylinder was only really long, would it ...
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117 views

Beat frequency for 3 waves

Consider 3 waves of frequency 101, 103, 106 hz, and of same intensity. What should be the beat frequency. Now I can calc it for 2 waves, and i know how to write the combined equation of the two. But ...
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124 views

Minimum spread of frequency and wavelength in neodymium laser

What is the equation linking the minimum spread in wavelength and frequency of a pulsed laser, in relation to the lasers pulse time and operational wavelength. For example: If a Neodymium laser ...
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34 views

Unusual waves and one of its parameter

I'm messing up with this java app on the web about waves on a string and i'm really curious about something. The java app is the following : ...
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83 views

Frequency dependance of sound wave reflection

Why are high frequencies reflected more than low frequencies off an 'acoustically hard' surface such as concrete? I basically understand that the amount of reflection is determined by the impedance ...
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169 views

How do you super impose two or more signals to occupy a fix area of space with the resultant summed wave?

Is it possible to super-impose two or more signals all sent from different directions as a standing wave with the resulting summed wave occupying a fix area of space that is also a complex area? Do ...
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72 views

What phenomenon is responsible for the evolution pattern of waves created by waterfalls?

I have been fascinated lately by the pattern of the waves created by a waterfall in my town. Specifically, the pattern shows a gradual decrease in the density of the waves as they travel away from ...
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13 views

Determining photon flux at a particular distance from a source, given frequency and transmitter wattage

I want to check my process and formulae for determining the observed number of photons per square meter per second, when the signal frequency is $f$, transmitter power is $P$ and the distance from the ...
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19 views

How to compare natural frequencies for different pendulum-spring systems oscilating around the vertical equilibrium?

Im trying to compare the natural frequency of different pendulum oscilation systems around the vertical equilibrium. For the first case the balance of momentum is very simple and the natural ...
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15 views

What's the difference between frequency, spectral and cepstral domains?

I have a hard time teasing apart the conceptual difference between these three domains, and constantly mix them up in my head. I've been reading up on it, but I can't wrap my head around it. a ...
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30 views

What is the frequency associated to the orbitals within an atom?

I was told that there's a vibrational frequency associated to the orbitals within an atoms, but it is a frequency related not to a classical vibration. What Hz frequencies would these be?
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54 views

EM wave frequency vs. attenuation

Why does increasing frequency of an EM wave (for example in sea water with positive and negative ions floating about) increase the attenuation of the wave? Is the relative permittivity changed or the ...
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33 views

How power spectral density in time domain can be understood?

I got some data which basically gives me the variation on the time of a PSD measured across specific frequency bands ranges, for instance [10Hz-30Hz]. However I have not found any good explanation ...
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15 views

What is the effect of a magnetic field on a plasma speaker?

I have been doing some research for the past couple years investigating the effect of a magnetic field on a plasma speaker. More specifically, if you apply a relatively uniform magnetic field in no ...
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53 views

The affect of high frequency and high voltage AC on induction

I am designing an induction system to wirelessly transfer power a short distance. I was planning on using resonant inductive coupling to increase the efficiency. The Inductance of my coil is about ...
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22 views

intuition of negative temporal frequency

Assuming we have f_t=-7 in a 3-D environment. how can I interpret it? I think sing of temporal frequency is how many cycle is our movement to the left or right? is it right interpretation?
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73 views

why Angular Frequency is useful in comparison with spatial frequency in video?

what is difference between angular frequency and spatial frequency when we are talking about eye perceiving in a video. In many texts about video (for example Yao Wang's Video Processing and ...
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51 views

Extremely long wavelength electromagnetic radiation

High frequencies are used to eject electrons, because only electrons can really be affected at such a small wavelength scale. But could an electromagnetic wave have such a ridiculously low frequency ...
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37 views

Calculating the frequency produced by a rectangular piece of metal

I have a rectangular prism made of steel. Its dimensions are 0.1 cm x 0.2 cm x 12 cm. If I screw one end to a stable object and vibrate the other end. How would I calculate the frequency produced by ...
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47 views

What properties affect the color of item?

I already understand how gap bands work and how atoms can absorb/reflect light. I also already understand that rough objects will reflect light differently in comparison to smooth objects, but I do ...
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49 views

What is the best laser wavelength to melt a certain material to the point of 'welding' together

Assume the material is enough of a heat sink that you can hold the torch to the material and the spread of the red-hot metal is not moving - is stabilized, but you can still melt the material in the ...
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141 views

Source of low frequency oscillation heard in ambulance siren

I have noticed that when I am standing on the street as an ambulance passes that so long as it is sufficiently close by (within 10-15 feet, so the siren is VERY loud for this to happen), I hear a ...
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29 views

Varying vibration frequencies

Im currently testing vibrations through materials. I have a vibration motor that runs 200hz. Problem; the pressure I apply to the motor change the frequencies I pick up. Why? Example: If I use a ...
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44 views

Resonance force with multiple emitters

Will I get a stronger resonance if I put multiple frequency generators around the same object? example image
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33 views

How to represent a multiple in the frequency domain

So, in my previous question Where does this formula for prediction of a multiple wave come from?, I get that using this picture: we have so far written the time it takes for a multiple to travel ...