Three Particles Lie on the X Axis: Particle 1, with a Charge

Multiple Choice

Three particles lie on the x axis: particle 1, with a charge of 1 * 10^-8 C is at x = 1 cm, particle 2, with a charge of 2 *10^-8 Cis at x = 2 cm, and particle 3, with a charge of -3 *10^-8 C, is at x = 3 cm. The potential energy of this arrangement, relative to the potential energy for infinite separation, is:

A) +4.9 *10^-4 J
B) -4.9 *10^-4 J
C) +8.5* 10^-4 J
D) -8.5 *10^-4 J
E) zero