Chapter 4.4, Problem 48E

Coulomb’s Law states that the force of attraction between two charged particles is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. The figure shows particles with charge 1 located at positions 0 and 2 on a coordinate line and a particle with charge −1 at a position x between them. It follows from Coulomb’s Law that the net force acting on the middle particle is

$F(x)=-\frac{k}{x^2}+\frac{k}{{(x-2)}^2}0<x<2$

where k is a positive constant. Sketch the graph of the net force function. What does the graph say about the force?