Infinite square-well potential

[Kurt12]

Homework Statement

Consider an electron trapped in an infinite square-well potential. If the width of the well is equal to the position uncertainty, what would be the lowest energy level for this electron

Homework Equations

The Attempt at a Solution

I tried the equation for energy of a particle in a box but it requires the width and I don't know how to use the given fact that it is equal to the position uncertainty. Any help is greatly appreciated.

 

[vela]

The problem wants you to use the uncertainty principle to estimate the momentum of the particle and find its corresponding energy.