College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 49

How fast must an electron be moving if all its kinetic energy is lost to a single x-ray photon (a) at the high end of the x-ray electromagnetic spectrum with a wavelength of 1.00 × 10 8 m and (b) at the low end of the x-ray electromagnetic spectrum with a wavelength of 1.00 × 10 13 m