(iii) Electromagnetic radiation of wavelength 580 nm is incident on an uncharged surface of a metal X, in vacuo. Electrons are ejected from the metal surface and are attracted to a nearby positively charged electrode causing a photoelectric current to flow. As the potential on the nearby electrode is decreased, the photoelectric current decreases and becomes zero when the electrode potential is -0.3 V. Calculate the maximum velocity of the photoelectrons ejected from the metal surface.

(iii) Electromagnetic radiation of wavelength 580 nm is incident on an uncharged surface of a metal X, in vacuo. Electrons are ejected from the metal surface and are attracted to a nearby positively charged electrode causing a photoelectric current to flow. As the potential on the nearby electrode is decreased, the photoelectric current decreases and becomes zero when the electrode potential is -0.3 V. Calculate the maximum velocity of the photoelectrons ejected from the metal surface.