2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/89565Exact solutions of several nonstationary problems of quantum mechanics are obtained. It is shown that if the initial conditions of the problem correspond to the localized-in-space particle, then it moves exactly along the classical trajectory, and the wave packet is not spread in time.3 pagesQuantum Physicstext