Two-point charges q1 = +2.35 nC and q2 = -6.75 nC are 0.100 mm apart. Point A is midway between them; point B is 0.080 mm from q1 and 0.060 mm from q2. Take the electric potential to be zero at infinity. Find the potential at point A. Find the potential at point B. Find the work done by the electric field on a charge of 2.20 nC that travels from point B to point A.