Question

We set the potential energy in the particle in the box equal to zero and justified it by saying that there is no absolute scale for potential energy. Is this also true for kinetic energy?

Answer 1

As a particle in a one dimensional box moves back and forth between the two walls, the average momentum is zero and thus , the kinetic energy is zero.

Step-by-step explanation:

Kinetic energy is express as

E(kinetic) =
`E_k = (1)/(2) mv^2\\Therefore\\E_k = (1)/(2) mv^2 * (m)/(m) \\E_k = (1)/(2) (m^2v^2)/(m) \\E_k = (1)/(2) (p^2)/(m) \\Thus\\E_k = (1)/(2) (p^2)/(m)`

As a particle in a one dimensional box moves back and forth between the two walls, the average momentum is zero and thus , the kinetic energy is zero.