1. The problem statement, all variables and given/known data The electric field associated with a monochromatic beam becomes zero 1.2*10^15 times per second. Find the max kinetic energy of the photoelectrons when this light falls on a metal surface whose work function is 2.0 eV. 2. Relevant equations 3. The attempt at a solution K(max)=hv-W where W=work function. I have to find frequency from the given information which I don't know. But I guess it should be 1.2*10^15. Not sure about that.