Problem 3
Monochromatic light in vacuum has frequency f and wavelength λ. A light photon is described using Planck’s constant h and the speed of light c=3.00×10⁸ m/s; ignore interactions with matter. (a) Relate f and λ through wave propagation. (b) Derive one photon’s energy E_γ in terms of f and then λ. (c) Find momentum magnitude p_γ and check dimensions of E_γ and p_γ. 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.