Andrews, Mark2015-12-172015-12-170002-9505http://hdl.handle.net/1885/95087For a nonrelativistic particle acted on by a spatially uniform but possibly time-dependent force, or for a harmonic oscillator also subject to such a uniform force, the wave function differs from that without the force only by a spatial displacement and a phase factor. The shifts in position and phase are simply derived from a solution of the classical equations of motion.© 2010 American Association of Physics Teachers. Publisher permission to archive the version was granted via email on 19/11/2015. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in American Journal of Physics and may be found at https://doi.org/10.1119/1.3481703201010.1119/1.34817032016-02-24