Three charges sit at the corners of an equilateral triangle with sides of length d = 3cm. The magnitudes of the charges are q1 = +2nC, q2 = ?1nC, q3 = ?1nC.
a) Calculate the potential energy of this system.
b) Explain the sign of your result from part (a) (i.e. why it is positive or negative).
c) Calculate the electric potential at the centre of the triangle,