1. The problem statement, all variables and given/known data Four identical point charges (+4.0 mC) are placed at the corners of a square which has 20-cm sides. How much work is required to assemble this charge arrangement starting with each of the charges a very large distance from any of the other charges? 3. The attempt at a solution I want to know if this is the right formula and answer: U=K(q1q2/r12 + q1q3/r13 + q1q4/r14 + q2q3/r23 + q2q4/r24 + q3q4/r34) i got 3.9 as the answer.