Three point charges, -1 RC, 1 nC, and +2 nC, are arranged in an _1 DC equilateral triangle as shown. If the l nC charge on the lower left is . removed to infinity, would the potential energy of the 3-particle system increase, decrease, or remain the some? Explain. (Note: \"Removed to . . ,, . d d innity means that an external agent, for example a person s hand, moves the l nC point charge away until it is a very large distance from both of the other two charges.) Two \"source\" charges +q., and q0 are xed in place at the positions shown. Four locations A. B, C, and D are labeled on the diagram. a. Rank. from highest to lowest, the electric potentials at points A-D. Explain your reasoning. IHHIE b. A positive probe charge is now moved from point A to point B. a Is the work done on the probe charge by the electric eld due to the source charges positive. negative. or zero? Explain. - Is the change in electrical potential energy positive, negative, or zero? Explain