Relation between Energy and frequency

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Discussion Overview

The discussion revolves around the relationship between energy and frequency, particularly in the context of classical and quantum mechanics. Participants explore how changes in frequency affect energy, with references to different types of waves and systems.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the validity of the original question regarding the change in total energy when frequency is doubled, suggesting two perspectives: classical and quantum.
  • Another participant expresses confusion about the context of the question, asking for clarification on whether it pertains to a laser, power grid, or audio amplifier.
  • A participant introduces a formula related to energy in a classical context, but expresses uncertainty about its validity and the clarity of the original question.
  • Further elaboration on classical waves is provided, with a focus on how energy relates to amplitude and frequency, and the complexity of defining energy in different dimensional wave contexts.
  • There is a distinction made between classical wave energy, which may depend on time period rather than frequency, and quantum energy, which is described as quantized in terms of Planck's constant.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the original question's clarity or validity. Multiple competing views and interpretations of energy and frequency remain, particularly between classical and quantum perspectives.

Contextual Notes

Participants note the importance of context and definitions when discussing energy and frequency, highlighting that symbols and formulas may lack meaning without proper explanation. There are unresolved questions regarding the applicability of certain formulas and the definitions of energy in different scenarios.

gianeshwar
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Hi Friends!
Please tell me if the question below is valid?

"If the frequency of the source is changed from f to 2f ,keeping amplitude same,then total energy is changed by what amount?"
What I conclude is"We can think it in two ways:
1 In classical sense,where I could not find any such relation.
2 In microscopic(quantum) sense E equals hf where h is Plank's constant .So it can give answer as E if the Energy at f is E.
 
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Your question is very unclear. Are you talking about a laser? A power grid? An audio amplifier? Or what?
 
anorlunda said:
Your question is very unclear. Are you talking about a laser? A power grid? An audio amplifier? Or what?
Consider it in classical sense e.g water wave or rope being vibrated by hand when other end is attached to a wall etc.
I am not an expert but am very keen so please bear me.
I meanwhile stumbled upon a formula
E =pie square.n square.A square.v.
I still do not know its validity.
 
gianeshwar said:
Consider it in classical sense e.g water wave or rope being vibrated by hand when other end is attached to a wall etc.
I am not an expert but am very keen so please bear me.
I meanwhile stumbled upon a formula
E =pie square.n square.A square.v.
I still do not know its validity.

You seem to have a bit of a problem in presenting a very clear and complete question. It also appears that you are looking at some source and then asking things here.

I suggest you make a reference to the source, i.e. is this out of a book or from some website that you read? Then provide a link.

Secondly, "symbols" mean nothing without context. If I tell you that E in that equation is actually H, and that A square v equal to wk, will that makes ANY sense to you? No? Then look at what you've done!

Without proper definition and context, those symbols that you've typed are meaningless, and you've just wasted time and effort presenting something that not many people can understand.

Try to sit back, and look at what you've typed, and see if you are assuming that we actually know what's in your head.

Zz.
 
Thank You anorlunda and ZapperZ for responding! I will come back with my clear idea.
 
1D waves we can represent by amplitude as:
$$ y(x,t) = A\sin(\omega{t}-kx) $$
where energy depends from A2. On 2D or 3D waves we cannot difine the wave by amplitude, because this is not the same. Let we have circular waves on water surface by a source of power P. The wave function must be:$$ y(r,t) = \frac{A}{r}\sin(\omega{t}-kr) $$and we must calculate A by setting the energy gives the source in one period equal to energy have all vibrational particles in the first wavelength.
This is not easy but A can be calculated and the above function can be formed well.

Now if you want the energy for a classical wave, you must determine what energy talking for. This energy depends by the time period you add not by the frequency. For quantum electrodynamics this energy part cannot be anything but makes quanta of hν energy amount. (h is the Plank's constant).
 
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