Problem 3
A metal of work function is illuminated by monochromatic light of frequency ; photoemission occurs only if a photon has enough energy. Let Planck's constant be , the electron charge magnitude be , and define positive stopping voltage as the voltage just sufficient to stop the fastest electron. (a) Find threshold frequency . (b) Express maximum kinetic energy in terms of and give the emission condition. (c) Find and describe the slope and intercept of a plot of versus on the emission range.
problems.proof.stepOf
problems.proof.analysis
At threshold an electron just escapes the surface with zero kinetic energy. The photon energy therefore equals the work function.