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

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Phase difference of driving frequency and oscillating frequency

If 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's oscillation frequency. However I'm told that the phase ...
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1answer
76 views

Damping of not harmonic waves

You pluck a (guitar) string so that you create a wave with harmonic frequency and a wave with not-harmonic frequency. Which one will be heard longer? Why? Or ask it differently: Is the wave with ...
2
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1answer
47 views

pGRE question on natural line width

The lifetime for the $2p \rightarrow 1s$ transition in hydrogen is $1.6 \times 10^{-9}$ s. The natural line width for the radiation emitted during the transition is approximately... Their solution: ...
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2answers
194 views
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1answer
72 views

If wave speed is dependent on medium only, then how to reconcile $v\propto f$?

I have read and learnt in many places that velocity of a wave depends only on the medium through which it travels. It is clear from this that the velocity of a wave doesn't depend on the frequency of ...
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3answers
55 views

Voices of Animals And Humans

What are the differences between voices of animals and humans? (Not by ear but by a program or similar...frequency, other things) Does each animal in each species have a unique voice? Is there a ...
0
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1answer
38 views

How do I prove that frequencies that are irrationally related lead to quasi-periodic motion?

Consider the equation: \begin{equation} \dot{x} = Mx, \end{equation} where \begin{equation} M = \begin{pmatrix} i\omega_1 & 0 & \cdots & 0 \\ 0 & i\omega_2 & \cdots & 0 \\ ...
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7answers
3k views

Why is it so easy to create audible sound?

Context Why is it so easy to create audible sounds in life with basically anything? Putting your cup of coffee on a table comes with a sound Turning a page of your book comes with a sound Even ...
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2answers
2k views

Why does noise affect FM radio less than AM?

Frequency modulated waves are less susceptible to noise compared to amplitude modulated signal. This is because the information in an FM signal is transmitted through varying the frequency, and not ...
0
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0answers
37 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 ...
0
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1answer
53 views

One color frequency items

I asked a slightly different question before, but how common are one color frequency items? Many things can reflect many colors of light, but predominantly show one under white light. If they are ...
0
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1answer
33 views

Can a phase array evoke a standing wave at a focal point that has a much higher frequency that the constituent emitted frequencies?

This is a phased array: How can you focus sound? It can focus many waves of weak radio wave or light into a single focal point that's very strong. Now imagine that we delay half of the emitters by ...
3
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1answer
69 views

Why are some elemental materials grey?

How does grey occur in elemental materials such as metals? I believe that grey arises from the simultaneous reflection and absorption of all colors of the spectrum (in different atoms of course), as ...
0
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2answers
58 views

The Color White

How can something that is white reflect all colors? It would have to reflect all frequencies or at least blue green and red, correct? How can a two element compound, such as NaCl reflect all of these ...
0
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1answer
34 views

Reflections of objects of a particular color

How can any color reflect the color of light shone upon it? I tested this by shining different colors of light on different objects, and instead of becoming black, it reflected a hazier form of that ...
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0answers
41 views

Why is information transfer usually done through frequency modulation but not amplitude modulation [closed]

For example, if we were to transmit a sequence of code, we could do so by alternating the flash rate of the source, or alternate the strength of the source. Both methods can represent a large amount ...
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2answers
1k views

Refraction of light and frequency dependence

Why do higher frequency waves refract more, both ocean waves and light waves? Also why is energy stored in the frequency as opposed to the wavelength.
0
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0answers
39 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 ...
1
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3answers
76 views

How can frequency be constant during refraction? [duplicate]

When entering from a rarer to a denser medium, the speed of light decreases.I know that the frequency remains constant.But if frequency is cycles/sec then doesn't that mean more speed will lead to ...
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3answers
122 views

What does a constant signal sound like?

Say I was sampling a sound incorrectly and it produced a constant signal as below: What would this signal sound like? In Matlab, it plays nothing. Is this correct?
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5answers
24k views

Do low frequency sounds really carry longer distances?

It is a common belief that low frequencies travel longer distances. Indeed, the bass is really what you hear when the neighbor plays his HiFi loud (Woom Woom). Try asking people around, a lot of them ...
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0answers
115 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 ...
0
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2answers
38 views

How are different wavelength components collected by the same detector in a spectrometer?

Let's think, we have a detector array (128x1 and each CMOS detector responds 400 to 1000 nm TSL1401CL that way, each detector has 4.6875 nm interval). Then, basically in a spectrometer a prism reflect ...
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1answer
30 views

Question regarding frequency of pendulum while it is stopping

As a pendulum stops, the frequency increases, but of course the pendulum stops. So does the frequency increase so much that it... turns to 0? Or does this have to do with wavelength or speed?
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4answers
72 views

Frequency of a photon

in classical physics frequency represents how many cycles in one unit time, but I do not know how we define a frequency for a particle? what does it mean for a particle to have a frequency, the book I ...
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4answers
4k views

Why do prisms work (why is refraction frequency dependent)?

It is well known that a prism can "split light" by separating different frequencies of light: Many sources state that the reason this happens is that the index of refraction is different for ...
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0answers
27 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 : ...
3
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1answer
354 views

Giant Wind Chimes

I am building large wind chimes out of ALUMINUM TUBES with a D2 at 73.41 hertz as the lowest and two other higher frequencies of A2 at 110 hertz and E3 at 164.8 hertz. I know how to find each length ...
54
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8answers
36k views

Why does a remote car key work when held to your head/body?

I was trying to unlock my car, but I was out of range. A friend of mine said that I have to hold the transmitter next to my head. It worked, so I tried the following later that day: Walked away from ...
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2answers
102 views

Why need for 96kHz, 192kHz audio? [closed]

Human can hear 20-20,000 Hz waves, so by Nyquist theorem it's sufficient to sample audio with 40 kHz. Indeed, 44.1 kHz widely used. But what do we need higher sample rates for? 96 kHz, 192 kHz are ...
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0answers
38 views

Ultimate Planck Frequency [closed]

Is there an upper limit to the Planck Frequency? Does it simply depend upon the inverse of the Planck Time unit?
5
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1answer
245 views

Is it possible for photon to run in circle by its own gravity?

I have heard that gravity came from energy and momentum so photon has gravity too. Then there are theory state that photon has energy tied to frequency. So if a photon has very very high frequency ...
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1answer
40 views

How is spectrum controlled? [closed]

I understand that spectrum is considered a national resource for many governments. It is akin to land, water and other resources. It is also a scarce resource. I wonder how is it that government ...
2
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1answer
37 views

Frequency of an open air column

Given only the length of an organ pipe to be $2.14 m$, is it possible to find what frequency it vibrates at? If I use the equation $f=\frac{v}{\lambda}$, does the $v$ apply to the speed of sound in ...
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1answer
294 views

Why doesn't frequency change? [duplicate]

I've seen a mathematical example where a wave was made from same source in water and air. but in both medium frequency was same but wavelengths were different in each medium. we know that velocity of ...
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2answers
67 views

What is energy of light, as we know speed of light?

1.What is total energy of EM waves, as all got same speed? If two em waves has same energy, do they have same mass? If same mass and energy, do they have same frequency or wavelength still ...
0
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1answer
144 views

What influences the intensity of a wave? Frequency vs Amplitude

So, in school, I have been taught that $I$ is proportional to $A^2$. However, when I look at the equation $E = h\cdot f$, I see the frequency has an impact too on the intensity! Now, if a sound wave ...
0
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1answer
44 views

Beam of electromagnetic wave, with radius of 3cm or less

I need to create a beam of electromagnetic wave, with radius of 3cm or less, for distance about few meters. What is the minimum frequency (maximum wavelength) that it is really possible?
2
votes
2answers
81 views

Resonance of a tube of air in case of more complex shapes

I've been thinking about posting this question on Music Performance stack, but finally I think it fits more here since I'm interrested in technical details. The subject of resonance of a tube of air ...
0
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3answers
1k views

Why frequency is inversely proportional to time-period?

Why frequency is inversely proportional to time-period? While studying about Fourier transform that shows frequency representation. A doubt that came to me was a set of signal with same wavelength ...
9
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5answers
20k views

Why frequency doesn't change during refraction?

When light goes through one medium to another it's velocity and wavelength changes. Why frequency doesn't change in this phenomenon?
0
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0answers
92 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 ...
0
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1answer
42 views

Wave frequencies and barrier width?

I know a fact that says a wave can go through barriers thinner than its length. This is why for example FM radio can be picked anywhere while antenna TV needs direct sight to the transmitter. Is this ...
1
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1answer
46 views

Explain why the frequency cutoff for RL circuits is given by $\frac{R}{2\pi L}$

I am studying low and high pass RL filters for Navy schooling. I need someone explain why the frequency cutoff is $fco = \frac{R}{2\pi L}$ mathematically. From my oscilloscope lab results I got the ...
0
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1answer
20 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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2answers
2k views

Frequency Of Light

I am confused on few topics... What is meant by "Frequency of Light"? Does the Photon(s) vibrate, that is known as its frequency? If the Photons vibrate, then they have a specific frequency, then ...
3
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2answers
99 views

Is there a way to create a flickering frequency to be dependent on speed of the person looking at it?

Is there a way to make a screen or a road sign flash at different rates, depending on the velocity of the observer looking at it? I would like to achieve a state where two observers going at ...
1
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0answers
65 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 ...
2
votes
1answer
49 views

How can Wien's Displacement Law be 'changed' to a version for frequency?

Wien's Displacement Law stated that for a blackbody emitting radiation, $$\lambda_{max}=\dfrac{1}{T}$$ where $T$ is the temperature of the body and $\lambda_{max}$ is the maximum wavelength of ...
2
votes
2answers
157 views

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 ...