Electromagnetic radiation of wavelength 4.50 x 10^-7 m and intensity 800Wm^-1 is incident on the surface of a metal with work function of 2.02eV. Electrons are emmited from the surface and attracted to a positively charged electrode with a p.d. of 10V. Question: Assuming that each photon liberates an electron, estimate the pressure exerted by the photoelectrons on the positive lectrode which has an area of 3.0 x 10^-4m^2. ( You may assume that all the photoelectrons emmited are absorbed by the positive electrode.) In the exam, I gave the answer in terms of distance, d, which is the distance between the metal and the positively charged electrode. Am I right to say that this question is unqorkable if no distance is provided?