Practice Problem on Electrical Potential for Point Charges



                     Q1=-4 micro-C
                           o
                          / \
                         /   \
                        /     \
                       /       \
                      /         \
                     /           \
                    /             \
                   /               \
                  /                 \
   Q2=+1 micro-C o-------------------o P3           
                 |------- 4cm -------|



2 charges are arranged on an equilateral triangle as shown above. What is the electrical potential (voltage) at P3? Specify your answer to three significant places.

ANSWER = ( V = -6.74e+5 V )