All Questions
96
questions
3
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5
answers
218
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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
1
vote
3
answers
171
views
How to Measure Energy of a Electromagnetic Wave accounting also for frequency?
We know a way of measuring energy of a electromagnetic wave is the Poynting vector, which is independent of the frequency. But let's say we want to make two different electromagnetic waves, with ...
2
votes
8
answers
971
views
Why does a higher frequency mechanical wave have more energy?
(that question may sound like my last question What makes a higher frequency sound wave more energetic? but I wouldn't consider it a duplicate, the focus is very different.)
Comparing two mechanical ...
- 211
1
vote
1
answer
478
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What makes a higher frequency sound wave more energetic?
The energy of a mechanical wave (in this case, the sound wave, which stimulates periodic movements of a gas) is proportional to both amplitude and frequency. Often, I read that it is written that ...
- 211
2
votes
2
answers
207
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Does the formula $E = hf$ apply to all electromagnetic waves?
The formula $E=hf$ shows the energy contained in one photon. Here, we use the simple half wave dipole antenna to evaluate the energy of photons at different frequencies. Surprisingly that gives a ...
- 31
0
votes
2
answers
166
views
Is the intensity of a light wave related to frequency of the wave?
My problem is: How can I resolve these following ideas?
Energy of photons in an EM wave is proportional to the frequency of the wave
Intensity of an EM wave is proportional to the energy that is ...
- 15
0
votes
1
answer
68
views
Very confused about pulse-echo measurements
Heres a link to the question im referring to just in case the image is not visible in the post - https://ibb.co/2vsZy90
Can someone please this mark scheme answer in simple terms. Firstly, what ...
- 105
1
vote
2
answers
223
views
Relation between frequency of vibrator generator and frequency of waves in a stretched string
Imagine a vibration generator is attached to a stretched string. Will the frequency of the vibration generator be equal to the frequency of the waves produced in the stretched string?
Also, a similar ...
- 105
0
votes
1
answer
116
views
Changing frequency of light without changing its energy
Three observations were detected in the photo-electric effect:
The kinetic energy of the ejected electrons doesn't change if you change the intensity of light (instead more electrons are ejected with ...
- 61
2
votes
3
answers
175
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Physical Significance of Frequency of matter waves
So, in our book there was an additional exercise part and this question baffles me:-
Q. Answer the following questions:-
The energy and momentum of an electron are related to the frequency and ...
- 31
1
vote
2
answers
131
views
Does the sign on the exponentials matter in the solution of Dirac's equation?
The general solution of the Dirac equation is a linear combination of plane waves. The Positive Frequency Solutions are of the form
\begin{equation*}
\psi(x) = u(p)e^{-ipx},\quad\text{with}\quad p^2 = ...
- 1,783
14
votes
8
answers
4k
views
Why does high frequency have high energy?
The electromagnetic spectrum's wavelengths all travel at the same speed, $c$. Also, the wavelength $\lambda$ and frequency $\nu$ are related by $c = \lambda \cdot \nu$. Since all moving particles here ...
- 259
1
vote
0
answers
77
views
Understanding the phrase "Classical mechanics corresponds to the high frequency limit of quantum mechanics"
Recently I have taken an interest in mathematical physics and as my background is mostly in math itself, I have quite a lot of catching up to do regarding my knowledge of physics. One phrase that I ...
- 149
-2
votes
1
answer
1k
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A mathematical derivation of $E = hv$? [closed]
Though at its origin, the formula for the energy of a photon $\varepsilon=hv$ is a postulate, is there a way of proving this formula mathematically, with consideration of Newtonian mechanics and the ...
- 633
1
vote
2
answers
354
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Are gamma rays the limit of the frequency photons can attain, and if yes, why? [duplicate]
Recalling that the Planck constant is $6.62607015 \times 10^{-34} m^2kg/s$ and taking into account the formula $E=hf$, for the energy of photons, we can rapidly derive the energy of gamma rays, which ...
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