On illuminating a metal surface by $$ 8.5 \times 10^{14} Hz$$, the emitted-electron's maximum kinetic energy is $$0.52\,eV $$. For the same surface on illuminating with light of frequency $$ 12.0 \times 10^{14}\,Hz$$, the maximum kinetic energy of photoelectrons is $$ 1.97\,eV$$. Find out the work function of the metal.