Particles with the charges -5.0 µC and +5.0 µC respectively are placed at the ends of the 8-cm base of an isosceles triangle. A third point charge (15.0 µC) is placed at the vertex of the triangle. The two other sides of the triangle are 4 cm each. What is the electric potential at the midpoint of the base of the triangle?

Particles with the charges -5.0 µC and +5.0 µC respectively are placed at the ends of the 8-cm base of an isosceles triangle. A third point charge (15.0 µC) is placed at the vertex of the triangle. The two other sides of the triangle are 4 cm each. What is the electric potential at the midpoint of the base of the triangle?