1. The problem statement, all variables and given/known data Charges of -q and +2q are fixed in place, with a distance d = 6.00 m between them. A dashed line is drawn through the negative charge, perpendicular to the line between the charges. On the dashed line, at a distance L from the negative charge, there is at least one spot where the total potential is zero. Find the distance L. http://edugen.wiley.com/edugen/courses/crs1507/art/qb/qu/c19/qu_19.62.gif 2. Relevant equations Vtotal = kq1/r1 + kq2/r2 3. The attempt at a solution Since i'm looking for when vtotal = 0 then -kq/r1 = k2q/r2 I'm lost as to where to go from here, I can't figure out how to use the d=6m. Any help is appreciated!