Questions tagged [frequency]
Frequency is the rate of repetitive aspect in the amplitude over a given dimension.
1,502 questions
1
vote
2
answers
53
views
What is the exact nature of molecular vibration in solids and how does it relate to an object's natural fundamental resonant frequency?
This is my understanding and trail of thought on the topic in the title, and I would like to hear from others with a better understanding of the subject if I am on the right track or not.
I will begin ...
- 11
0
votes
0
answers
29
views
Planck's Law frequency vs wavelength [duplicate]
I was plotting planck's law today and attempted two different implementations. I took both from this table on Wikipedia. They are:
In terms of wavelength:
$$
B_{\lambda }(\lambda ,T)={\frac {2hc^{...
- 203
-1
votes
1
answer
46
views
Theorized tone of two engines combined
Assume 2 of the exact same engine types at the same rotational speed producing the same tone. Lets say the exhaust of each engine gets combined in a uniform length y pipe into one output.
If these two ...
41
votes
10
answers
7k
views
Why aren't we bumping into objects outside of the visible range?
Apologies if this is too simple of a question for this site. My physics education stopped at the undergrad level. My 12 year old nephew asked me a question and I couldn't give him an answer. He asked, ...
- 519
-2
votes
0
answers
43
views
What is the shortest/longest wavelength of a photon? [duplicate]
What are the largest/smallest possible wavelengths of photons? I am interested in what limits apply to photon creation.
0
votes
1
answer
58
views
What is the general energy expresion for a massless particle?
The general energy-momentum relation for a massless particle is $E=cp$.
I know that for a photon we have $E=hf$. Is this relation valid for any massless particle?
- 416
0
votes
0
answers
22
views
Melde's Experiment Nodes and Frequency
Can someone please explain why in Melde's experiment, the number of nodes in the transverse wave is double the number of nodes formed in the longitudinal wave?
And also the derivation of the frequency ...
- 1
0
votes
2
answers
78
views
Why aren't brightness and loudness represented as spectra? [closed]
I'm curious why brightness (light intensity) and loudness (sound intensity) aren't usually described using a spectrum, which typically shows frequency ranges. Are these quantities measured differently ...
0
votes
2
answers
97
views
If the current frequency is within the human hearing range, why can't we hear it?
If the current frequency (50 Hz or 60 Hz) falls within the human hearing range (20 Hz to 20 kHz), why can’t we hear it?
1
vote
0
answers
25
views
How to calculate the effective permittivity of a material exposed to an electric field of a square wave? [closed]
Sorry if this is more of an engineering question, but i think it fits the forum.
I want to calculate the capacitance of a capacitor which is made out of a comb like structure (compare the ascii art ...
- 33
4
votes
1
answer
86
views
On a major scale why are there half steps between B and C and between E and F? [closed]
On a major scale why are there half steps between b and c and between e and f?
It seems like from a to b to c to d to e to f to g to a should all differ in the same "amount" of tone from ...
4
votes
1
answer
192
views
What is "the frequency" of a wavepacket?
I'm making a numerical simulation of a transmission line, based on the Telegrapher's equations. And in particular of how pulses move through a cable. Currently I'm trying to understand how dispersion ...
- 43
0
votes
1
answer
37
views
Dependence of Wave frequency
I recently came across a question where a wave huts a wall reflects and it's intensity becomes 0.64 times the original.
Intensity depends on frequency and amplitude.
Now after reflection could the ...
- 66
0
votes
1
answer
64
views
Energy of light as EM wave and photon
In electrodynamics, light as a wave has an intensity $I = \frac{1}{2} c \epsilon E^2,$ where $E$ is the electric field amplitude.
Meanwhile in quantum mechanics, we study $I = \frac{dn}{dt} \frac{hc}{\...
- 11
1
vote
0
answers
29
views
Can we obtain any information from the rotating motion of the dipole?
When a distribution of electric charges rotates, it generates an electromagnetic field, which can interact with a magnetic dipole to induce rotational motion. Is there any relation between the ...
- 311
0
votes
0
answers
22
views
Dimensionality of the Hubble constant [duplicate]
According to Wikipedia,
The Hubble constant is most frequently quoted in (km/s)/Mpc
Since both km and Mpc are lengths, dimensionality of the Hubble constant comes out 1/time, i.e. frequency. As such,...
- 523
1
vote
1
answer
114
views
Final frequency with two waves combined
According to what I have been reading in various places, when we combine two close non-harmonic frequencies, we get the beating effect and a resulting frequency as the average of both frequencies. ...
- 11
1
vote
1
answer
91
views
Linewidth of the Caesium clock
The second is defined as
I am confused as the hyperfine transition frequency is not fixed, i.e., it has a finite linewidth. The frequency is not well defined.
Is it because the linewidth is very ...
- 2,165
1
vote
2
answers
120
views
Differential form of Planck's Distribution Law interpretation
So I didn't encounter differentials that often until now, I was taught that the seperate parts of $dy/dx$ for example are not supposed to have any sort of independent existence - ok.
(Calculus, 4th ...
- 153
0
votes
3
answers
117
views
Can refraction change a wave's frequency?
Can refraction change a wave's frequency under any circumstances ?
If yes, what conditions must apply for this to occur ?
Is this a common phenomenon or only happening in extreme circumstances (such ...
- 554
0
votes
1
answer
40
views
What really is natural frequency and resonance?
Shouldn’t the frequency of an object depend on how much I push it from one end if the other end is attached?
And what’s resonance? In my textbook there is no such explanation to what is actually is ...
1
vote
0
answers
72
views
Why can't one-way speed of light be derived with simple wave mechanics? [duplicate]
If we understand light as having a frequency and wavelength, why not just multiply them to get the speed, this doesn't require mirrors or synchronised clocks. I'm 100% sure this doesn't work, but I ...
0
votes
1
answer
60
views
What is the frequency of a standing wave? [closed]
I understand that constructive interference of waves results in standing waves. And for a wire with both ends fixed the frequency should match the fundamental frequency of the wire to produce standing ...
- 91
0
votes
1
answer
53
views
What is the mathematical support for the formula $f_n = n f_1$, used to calculate the frequency of a standing wave? [closed]
could someone explain to me the mathematical support for the formula $f_n = n f_1$. This formula refers to the fact that the frequency of a standing wave is equal to the number of antinodes times the ...
11
votes
4
answers
2k
views
Can the laser light, in principle, take any wavelength in the EM spectrum?
Can the laser light, in principle, take any wavelength in the EM spectrum? I don't think there is what prevent this in principle, right?
- 1,035
0
votes
0
answers
20
views
Wavelength and frequency of the peak of the black body radiation [duplicate]
Why does the product of the peak wavelength and the peak frequency of Planck's black body radiation not equal to the speed of light?
$$λ_{\mathrm{max}}=\frac{hc}{4.97\mathrm{kT}},$$ while $$ν_{\mathrm{...
- 121
0
votes
0
answers
71
views
Why does this RLC behavior differ from what equations predict?
In order to better understand RLC behavior under current sources, I constructed the simple circuit below and attempted to analyze it. However, my equations do not agree with simulation results.
The ...
- 309
0
votes
1
answer
68
views
Changing the frequency of the tuning forks
I just bought some tuning forks with frequencies of 128 Hz and 512 Hz. However, when I tested them using an app, their frequencies turned out to be lower than the specified values. How can I increase ...
- 1
0
votes
1
answer
84
views
Phase-Based Ranging
I've been reading a lot about Phase-Based Ranging (PBR), and it's all starting to become very intuitive.
BUT; There is one technical, but extremely important, detail that seems to escape me. When the ...
3
votes
2
answers
210
views
Angular frequency vector, when explaining the motion of a wave
The wave number $|k|$ results as the magnitude of the wave vector $k$. Is there an analogous vector from which the angular frequency $\omega$ results when the magnitude is formed? If yes, how can you ...
- 35
0
votes
0
answers
69
views
How to measure the vibration of an object on a video shot at high speed camere?
I have a video fragment which I split into frames (pictures). I use them in pairs (1 frame with 2, 2 with 3, etc.) to find shifts on x and y axes (i.e. how much I need to shift 1 frame to make it like ...
0
votes
0
answers
40
views
What are the different types of resonances in forced oscillation systems?
I'm currently studying resonances in systems subjected to forced oscillations and have come across various terms and cases that I'd like to understand more clearly. Specifically, I am analyzing a ...
0
votes
1
answer
67
views
Is there any deeper explanation behind this simple acoustic experiment?
my question is a bit inconvenient but let me explain:
I recently saw an experiment for primary school where two strings are attended to a coat hanger (see here: https://www.youtube.com/watch?v=...
- 308
1
vote
1
answer
143
views
Why does the phase difference of the capacitor voltage change with AC frequency?
In the graph below, the left vertical axis of the graph is the magnitude of voltage, the green line indicating the input voltage, blue line indicating the capacitor/inductor voltage. The right ...
- 23
0
votes
0
answers
28
views
Can anyone please give some explanation in terms of the frequency domain of the time evolution?
This might be a silly question. But I was puzzled for a long time, even some comments are greatly appreciated.
Is it possible to claim that "All the time domain evolution can be thought of ...
- 138
1
vote
1
answer
100
views
Why does the energy (and thus frequency) of a photon entering glass stay constant if some is used up to accelerate electrons and slow down the light?
I'm learning optics and have been told that when light enters a medium (e.g. glass) and slows down the frequency of the light stays constant while it is the wavelength which is reduced. The ...
- 531
0
votes
2
answers
105
views
I don't understand intuitively why the instantaneous frequency is obtained by calculating the time derivative of the phase
I don't understand intuitively why the instantaneous frequency is obtained by calculating the time derivative of the phase
- 11
0
votes
2
answers
99
views
Does sunlight have a modulation frequency?
By frequency, I don't mean electromagnetic frequency, I mean modulation frequency. For example, I can put a PWM square wave on an LED at some frequency, which I can detect with a photodiode and a ...
- 1
-1
votes
2
answers
119
views
What's the difference between the different kinds of EM waves?
I am an A-level student.
We have traditionally been taught that different types of EM waves exist only between certain ranges of wavelengths and frequencies.
However, I learned that electromagnetic ...
1
vote
1
answer
56
views
Why do we see objects with a given color?
I'm currently studying Electromagnetic Optics, and I don't quite understand the (classical) process through which we perceive an object with a given color. From my understanding, I'd make a ...
- 1,880
0
votes
0
answers
76
views
Who wrote $c = λ ν$ for the first time and where can I find it?
I have been surfing for days and still I could not find who wrote the equation $c=λν$ for the first time. Neither I found a name for this equation. A lot about Planck's constant and energy related ...
0
votes
2
answers
75
views
General formula for the frequency
The orbital period of a satellite is the time it takes to complete an entire orbit around the celestial body around which it orbits. I know that the orbital period using the following formula:
$$T = \...
- 2,575
3
votes
5
answers
268
views
Why Does Planck's Relation $E=hf$ Imply a Linear Relationship Only for Sinusoidal Frequency Bases?
I have been studying quantum mechanics and I came across Planck's relation which describes the energy $E$ of a photon as being directly proportional to its frequency $f$, with Planck's constant $h$ as ...
- 85
0
votes
1
answer
47
views
Why are laser linewidths in frequency domain?
I am learning about the lasers and I find one thing confusing about the lasers.
I understand that there is a range of wavelength laser, it is never exactly monochromatic. So, I understand the concept ...
user390982
15
votes
6
answers
8k
views
Why color depends on frequency and not on wavelength? [duplicate]
To explain my question lets consider this example:
The wavelength of light in a medium is $\lambda=\lambda_{0}/\mu$, where $\lambda_{0}$ is the wavelength in vacuum. A beam of red light ($\lambda_{0}=...
- 2,557
3
votes
0
answers
92
views
Why do water surfaces have persistent "average wavelength" patches?
Have you ever stood above a river or lake and noticed that the surface has visible "patches"? It looks like the surface has different average wavelengths in some areas, leading to the light ...
- 131
2
votes
1
answer
143
views
How can the Rabi frequency be complex?
I've been doing some reading and came across a simple implementation of the Hadamard gate using Rabi oscillations of an atom in a laser field. However, the author mentions that it required the Rabi ...
- 45
0
votes
0
answers
33
views
What duration of a white noise burst is required for it to be "white" at a given frequency or frequency range?
I am running white noise bursts (with very short ramps on/off to prevent discontinuities) through underdamped resonant bandpasses which are tuned to any given $f_0$ and an underdamped $Q$.
Continuous ...
- 343
1
vote
1
answer
77
views
Is natural frequency a local or global property?
Some objects have a natural frequency. This can be anything from a metal ball to a table, etc. When we hit such an object, it will start vibrating with a certain frequency $f$. Because of damping the ...
- 1,502
-1
votes
1
answer
122
views
Should natural frequency be modeled using molecules?
Consider an object. This can be anything from a metal ball to a table, etc. Now this object has a natural frequency. When we hit the object, it will start vibrating with a certain frequency $f$. ...
- 1,502