An electron (mass: 9.11x10-31 kg; charge:1.60x10-19 C) moves from location A to location B solely under the influence of conservative forces. At point A, the electron has speed 8.61 x 106 m/s and potential energy 1.79 x 10-17 J. If the potential energy of the electron at point B is -3.42 x 10-17 J (note that the potential energy at point B is negative), what is the speed of the electron at this point?