1. The problem statement, all variables and given/known data The American physicist Robert A. Millikan (1868-1953) won the 1923 Nobel Prize in physics, in part for his work on the photoelectric effect. Assume that Millikan observed for a hypothetical metal a maximum kinetic energy of 0.535 eV when electrons were ejected with 431.7 nm light. When light of 258.6 nm was used, he observed a maximum kinetic energy of 2.52 eV. Using these results, calculate the work function, W0, for the metal, without knowing the value for Planck's constant. 2. Relevant equations Vo = [(h/e)*f]-(θ/e) where θ is the work function. 3. The attempt at a solution Frequency 1 (using wavelength 1) = 6.94927e14 Hz Frequency 2 (using wavelength 2) = 1.1601e15 Hz Delta Frequency = 4.65173e14 Energy 1 (using eV1) =8.571644e-20 J Energy 2 (using eV2) =4.0375e-19 J Delta Energy = 3.18032e-19 thus, Delta Energy over Delta Frequency gives me my experimental h... h = 6.83685e-34 Js That's all fine and good... but I have NO idea how to solve for the work function. Greatly appreciate a reply, this is my last question of the day.