What is E=hf: Definition and 14 Discussions

Hi there, I'm a bit confused about the E=hf equation for mass particle(f for frequency), and Lorentz Invariant (E^2 -p^2c^2=m^2c^4). The question is, which energy is it? Total Energy- Kinetic plus Rest, or only kinetic energy. Now, if it's total energy, then you get that a particle at rest...

As to E=hf I understand that a energy can be arbitrary in order of proportional packages to given frequency. But is there any equation in quantum mechanics which imply a freq to be quantized? Thanks a lot!

Hello! I've read that electrons can only absorb photons of exactly the right amount of energy to move to a higher energy level, if its to little or too much then it doesn't absorb it at all, so my question: How can electrons be liberated from an atom with Kinetic energy when they can't absorb...

In de Broglie's matter wave equation, a book(namely Concepts of Modern Physics) derived the matter wavelength by putting ##E=hf## and ##E=\gamma mc^2## as equals. However I thought that ##hf## was energy of a photon, not a particle. Aren't these two very different concepts?

Q. If a photon travels in an electric field(usually by a nucleus,such as ^12C),it can spontaneously disintegrate into an electron and a positron--known as pair production. A)Calculate the smallest possible photon frequency that produces pair production by assuming that both electron and positron...

I know what the letters mean, E = Energy of the photon, h = Planck's constant, f = frequency of the photon. But what does it mean for a particle to have a frequency, something that I'd associate with a wave. And what can you think Planck's constant is representing? Any replies would be much...

Ok so the equation E= hf about the energy of a photon, I'm having a problem understanding energies to do with photons. Since, E=hf ∴ 1/2mv2=hf. But if m=0 how can a photon have energy?

What is the derivation for E=hf and why did experimental observation of black bodies show that quantization of light was neccessary?

We have the famous Einstein's Relation E = hf. He originally used this relation for photons of light only. But de-broglie expanded the concept and postulated that every matter exhibits a wave phenomenum (called matter wave) which satisfies these two relations 1.\lambda = h / P 2. E = hf It...

then i want to know how to prove E=hf without any assumption but with our basic physics knowledge to prove the formula is actually explaining quantum physics theory....i still blur about the formula for quantum physics...thanks if someone help me out!

What is the difference between formulas E=p^2/2m and E= hf ?

How does a photon move.If it is a particle and moves in a straight line,what do we mean by its frequency in E=hf?

when you integrate the energy density (from electromagnetic field) times the differiential volume of the whole 3D space for a photon...would you get the energy of it? E=hf ? one more question... if there is a positive charge in 3d space... when i integrate the electromagnetic energy density...

On a couple of webisites I have seen that they have equated E=mc^2 with E=hf ... i.e hf=mc^2 But how can this be done when E=hf is describing the energy of a photon and E=mc^2 isnt? Also, can someone provide me with a derivation of de Broglie’s theorem ? Wavelength = h/momentum...