Separation between equipotential surfaces near an infinite charged plane

[ibaraku]

Homework Statement

An infinite plane sheet of charge has uniform surface density
sigma = 1.00nC. What is the separation between equipotential surfaces differing in potential by 10.0V


I just a push in the right direction, thanks

 

[Gear300]

An infinite plane sheet of charge carries uniform electric field through infinite space excluding the sheet itself. Find the electric field; the electric potential should simply be the scalar product of the electric field and displacement (when finding the electric field, note that the Gaussian formula is for closed surfaces rather than open planes, or, by theory, surfaces that receive all electric flux/field lines...that is...if I have the concept right).