Physic Labs

Problem 2

A charge qq moves from rest through a potential difference VV in vacuum. Find its final speed for mass mm, assuming nonrelativistic motion. Assume ideal objects and components, neglect unstated losses, and use SI units. (a) Derive the primary requested quantity from the appropriate law. (b) Analyze quantitatively how the result depends on the given parameters. (c) Check a physically meaningful limiting case and explain its meaning. State sign conventions, show reasoning, and check dimensions. (a) Calculate the requested quantity from the data. (b) Give the law or expression showing parameter dependence. (c) Examine a limit consistent with the model.
qV=Kf−KiqV=K_f-K_i
problems.proof.analysis

Rearrange algebraically and select the solution consistent with initial conditions and physical meaning. Check dimensions before interpreting the expression.

problems.proof.pitfall. Keep the sign convention and constraints consistent; do not replace a signed quantity by its magnitude without justification.