Chapter 23, Problem 23.54P

Identical charges q = +5.00 μC are placed at opposite corners of a square that has sides of length 8.00 cm. Point A is at one of the empty corners, and point B is at the center of the square. A charge q₀ = −3.00 μC is placed at point A and moves along the diagonal of the square to point B. (a) What is the magnitude of the net electric force on q₀ when it is at point A? Sketch the placement of the charges and the direction of the net force, (b) What is the magnitude of the net electric force on q₀ when it is at point B? (c) How much work does the electric force do on q₀ during its motion from A to B? Is this work positive or negative? When it goes from A to B, does q₀ move to higher potential or to lower potential?