Light of frequency `8.41xx10^(14)Hz` is incident on a metal surface. Electrons with their maximum speed of `7.5xx10^(5)ms^(-1)` are ejected from the surface. Calculate the threshold frequency for photoemission of electrons. Also find the work function of the metal in electron volt `(eV)`. Given Plank's constant `h=6.625xx10^(-34)Js` and mass of the electron `9.1xx10^(-31)kg`.