Two wavelengths λ_1=496 nm and λ_2=620 nm fall on a metal surface. Calculate the work function if the ratio of max speed of photoelectron is v_1:…

Two wavelengths $\displaystyle \lambda_1=496 \mathrm{~nm}$ and $\displaystyle \lambda_2=620 \mathrm{~nm}$ fall on a metal surface. Calculate the work function if the ratio of max speed of photoelectron is $\displaystyle \mathrm{v}_1: \mathrm{v}_2=\sqrt{2}: 1$ for corresponding $\displaystyle \lambda_1$ and $\displaystyle \lambda_2$ respectively. (Take $\displaystyle \mathrm{hc}=1240 \mathrm{eV}-\mathrm{nm}$ )