posted on 2020-03-04, 02:41authored byRogério Netto Suave, Erich Andrade Ferreira, José Alexandre Nogueira
Abstract In this work, we would like to point out how an usually recommended exercise in Quantum Mechanics textbooks can lead to a surprising result at first, and how the clarification of this surprising result can help to reinforce ideas of Quantum Mechanics. We consider the problem of a particle in an infinite square well which suddenly has its width doubled. The surprise arrives in the fact that different results can be obtained whether the well is considered non-symmetrical or symmetrical, even though both are physically identical, as it is well-known.