SoSolid said:But aren't X rays electrons that have lost energy and the release of energy is the x ray?
Dave said:You know E = hf = hc/(lambda) so you can work out the frequency.
The de Broglie wavelength is (lambda) = h / p
So, hc/E = h/p, i.e. p = E/c (and v = E/c^2 if I am relatively sober)
And since p = mc you can work it out.
Or use the relativistic relationship which links energy/rest energy/momentum. (can't remember)
daz said:X-rays are photons generated by firing electrons at metal.
MrMatteh said:under most circumstances, the speed will be 3x10^8. I can't see that being the question
perhaps its something to do with the photoelectric effect, difficult to tell from the OPs wording
Visage said:It may be questioning what the recoil velocity is - an atom of mass m emits a photon with energy E, at what speed does the atom recoil....that kind of question.
Visage said:Not quite. The method of creation has no bearing on the nature of the reulstant photon. X-Rays can also be created in inter-stellar collisions, for example, as measured by CHANDRA.