This is driving me crazy! The question goes as follows:
A proton is enclosed in a zone of length 2pm along the x-axis. The minimal kinetic energy of the proton lies closest to:
- 5eV (this is supposed to be the correct answer)
So first I calculate the energy level for a particle in a box which is given by the equation $E_n = p_n^2/(2 m) = (n^2 h^2)/(8 m L^2) $
Here $L$ is the length of the zone. So I find $E_1=94007.53 eV$..
So.. How do I relate this to the minimal kinetic energy?
-- EDIT 1 --
After the first hint from someone, I changed my calculations (I used the mass of an electron instead of a proton..) NOW I get $E_1 = 51eV$, which is still wrong..