The de-Broglie wavelength associated with a proton under the influence of an electric potential of 100 V is

Radiation of wavelength $$300 \mathrm{~nm}$$ and intensity $$100 \mathrm{~W}-\mathrm{m}^{-2}$$ falls on the surface of a photosensitive material. If $$2 \%$$ of the incident photons produce photoelectron, the number of photoelectrons emitted from an area of $$2 \mathrm{~cm}^2$$ of the surface is nearly