Dual Nature Of Radiation

When photons incident on a photosensitive material of work function 1.5 eV , the maximum velocity of the emitted photoelectrons is $8 \times 10^5 \mathrm{~ms}^{-1}$. The stopping potential of the photoelectrons is

(Mass of the electron $=9 \times 10^{-31} \mathrm{~kg}$ and charge of the electron $=1.6 \times 10^{-19} \mathrm{C}$ )