Problem 3
Monochromatic light of frequency f illuminates a metal with work function W. In Einstein’s model, each electron absorbs one photon of energy hf; the maximum kinetic energy K_max of emitted electrons is measured, with material losses neglected. (a) Write energy conservation for an emitted electron. (b) Find K_max and threshold frequency f₀, and state the emission condition. (c) Give stopping potential V_s and explain how increasing intensity at fixed above-threshold frequency affects emission. Use SI units throughout and treat components as ideal exactly as specified. State sign conventions when writing equations and retain units in final results.
problems.proof.stepOf
problems.proof.analysis
First identify the system, given quantities, and sign convention; this determines what is conserved or acts on the body. The stated idealizations exclude unmentioned forces or effects.