If we define zero potential energy to be at infinity (choosing C=0 for electric potential energy), the work, Wq2, that we must do on q2 to bring it from infinity to a distance, \(r_{12...If we define zero potential energy to be at infinity (choosing C=0 for electric potential energy), the work, Wq2, that we must do on q2 to bring it from infinity to a distance, r12, from q1 is given by the corresponding change in potential energy of q2: Wq2=ΔU=Ufinal−Uinitial=kq1q2r12−0=kq1q2r12 Note that the work is done by us (not by the electric field), so it has the same sign as the …
