1. The problem statement, all variables and given/known data I am supposed to show, using a classical argument, that the speed "v" of a particle in an infinite 1-D potential well is v= (nh)/(2mL) 2. Relevant equations 3. The attempt at a solution Doesn't the particle just reflect back and forth against the walls of the well with a constant speed that it was given initially? How can I classically argue that planck's constant is supposed to be in the velocity?