A 5.0-nC charge is at (0, 0) and a -2.0-nC charge is at (3.0 m, 0). If the potential is taken to be zero at infinity, what is the electric potential energy of a 1.0-nC charge at point (0, 4.0 m)?
Answer
1.5 × 10-8 J
3.6 × 10-9 J
1.1 × 10-8 J
7.7 × 10-9 J