# Stupid question on schrodinger equation

hyena
i know its a stupid question but im a beginner:
according to eisntein:
$$E=K+m_{o}c^2$$
but the plane wave solution yields that particle's KE is its total energy,where free particle has no potential energy. But where is the rest mass energy$$m_{o}c^2$$? Is it omitted?

## Answers and Replies

Mentor
Schrödinger's equation is non-relativistic.

$$E=\sqrt{p^2 c^2 + m^2 c^4}$$
and Taylor-expand in powers of $p$, we get
$$E=mc^2 + {p^2\over 2m} + \ldots$$