1. The problem statement, all variables and given/known data A point charge of +2.7 mC is located at the origin of a coordinate system and a second point charge of -7.8 mC is at x = 1.5 m. At what point on the x axis is the electrical potential zero? Calculate to 2 decimal places. 2. Relevant equations 3. The attempt at a solution net pot. diff will be zero at x=1/3. and at x = -1. pot. diff is a scalar qty. so u can directly add it. if the net potential diff at a pt (say at x,0) is zero, we have (k*3/x) - (k*6/(1-x)) = 0 2x=1-x x=1/3 Similarly for negative x, u can make n eqn: -(k*3/x) - (-k*6/(1+x)) = 0 which shal give u: x=-1 WHAT AM I DOING WRONG?