Problem 3
Monochromatic light of frequency illuminates a metal with work function . Using Planck’s constant and the positive elementary charge , find the maximum photoelectron kinetic energy and stopping potential when . Assume the string, pulley, electrical source, or optical apparatus is ideal as stated, and neglect any effect not specified. State a clear sign convention, identify the physical Keep one model and sign convention throughout. Reuse each intermediate result with the same convention, then check that the answer has the required physical dimensions. (a) Set up the physical relation. (b) Find an intermediate quantity. (c) Obtain the answer and check its conditions and units.
problems.proof.stepOf
problems.proof.analysis
At threshold, emitted electrons have zero maximum kinetic energy, defining the threshold frequency. This is consistent with the stated model and the chosen sign convention.
problems.proof.pitfall. Stopping potential is positive in magnitude and satisfies .