college physics,electric potential
posted by melody .
Four point charges, each with Q = 7.2 µC, are arranged at the corners of a square of edge length 3.6 m. What is the electric potential at the center of the square?
V? Please show me how to solve this.Thanks

electric potential is a scalar, that is, you can just add it. So figure the potential from one corner, multiply it by 4.
V=kQ/distance
distance=edge*sqrt2