posted by Anonymous .
An experiment is set up in which a copper surface is irradiated with high-intensity photons with a wavelength of 15.0nm. Electrons ejected from the surface are found to have a velocity of .548% of c. What is the binding energy of copper's most weakly bound electrons? What is the wavelength of a the lowest-energy photon which can free electrons from copper atoms? Please explain what i need to do, and what equation i have to use because this question is confusing me.