What is the Equilibrium Distance(d)? qCd⊙q E= (q+(q-)e2 B 4元eod dn dE dd =0 when E=Emin Take the derivative;solve for B and plug in to find Emin=E when d=do Emin (q+(q-)e2 = 4元eod。 -0 XIII-15What is the Equilibrium Distance (do)? d q+ q￾dE dd = 0 when E = Emin Take the derivative; solve for B and plug in to find Emin = E when d = do E = (q+ )(q− )e2 4 π εo d + B dn Emin = (q+ )(q− )e2 4 π εo do 1− 1 n       XIII-15