Long description

Two vectors, r subscript 1 and r subscript 2, are drawn from a point O. A charge q subscript 1 is placed at the tip of vector r subscript 1 and a charge q subscript 2 is placed at the tip of vector r subscript 2. A vector r subscript 1 2 is drawn from charge q subscript 2 to charge q subscript 1. A vector r hat subscript 1 2 is drawn from charge q subscript 1 and points in a direction parallel to vector r subscript 1 2.