Homework Statement
Consider first a free particle (Potential energy zero everywhere). When the particle at
a given time is prepared in a state ψ (x) it has
<x> = 0 and <p> = 0.
The particle is now prepared in Ψ (x, t = 0) = ψ (x) exp (ikx)
Give <p> at time t = 0.
It can be shown that in...