Three point charges +1 mC, +1 mC and -1mC are placed in three vertices of a square which has 2 m long sides. The picture depicts one positive charge at the left upper corner, negative at the left lower and positive at right lower corners of a square.
1. Find electric field (magnitude and direction)
2. Find electric potential (magnitude and sign) in the center of the square and in the middle of each side.
3. Find force acting upon negative charge. Please show detailed step by step approach to solving this problem and include calculations.