Physic Labs

Problem 3

Light of wavelength λ\lambda illuminates a metal with work function WW, where hc/λ>Whc/\lambda>W. Given Planck's constant hh and light speed cc, find the maximum photoelectron kinetic energy, stopping potential, and threshold wavelength. Model each stage with the appropriate conservation law or equation of motion; quantities stated as constant remain fixed during that stage. (a) Establish the governing physical relation for each stage. (b) Determine the requested observables from the stated initial conditions and constraints. (c) Check signs, dimensions, and the physical limiting behavior of the results.
λ0=hcW,λ<λ0\boxed{\lambda_0=\frac{hc}{W},\qquad \lambda<\lambda_0}
problems.proof.analysis

Apply the model consistently to each part, then check dimensions and physical limits.