Two fixed point charges

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Electric Force Field and Potential · Electric Force Field and Potential

Problem

Two fixed point charges, each of magnitude

+3.0\,\mu\text{C}

, are located on the

x

-axis at

x=-0.20\,\text{m}

and

x=+0.20\,\text{m}

. A third charge of

-3.0\,\mu\text{C}

is brought from very far away to the origin

(0,0)

and held there. What is the total work done by the external agent in bringing the third charge to the origin? (Take

k=8.99\times10^{9}\,\text{N\,m}^2\!\,/\!\,\text{C}^2

.) (a)

+0.81\,\text{J}

(b)

+1.62\,\text{J}

(c)

-0.81\,\text{J}

(d)

-0.40\,\text{J}