Calculate the velocity of electron ejected from platinum surface when radiation of 200nm fall on it. Work function of platinum is 5eV. $(1eV=1.6\times 10^{-19}J$)

Question

$\begin{array}{1 1}(a)\;6.54\times 10^5m/s&(b)\;5.5\times 10^5m/s\\(c)\;6.54\times 10^2m/s&(d)\;4.63\times 10^3m/s\end{array}$