The graph should look something like this http://en.wikipedia.org/wiki/File:12-6-Lennard-Jones-Potential.svg (the other information has nothing to do with what I ask though, only the shape of the graph for clarity sake) My question is, does resultant force = 0, or when potential energy is minimum occur during absolute zero only, if so then what is the kinetic energy? Is kinetic energy maximum, or simply zero since it is absolute zero. If I'm wrong about U = 0 occuring at absolute zero only please correct me. My second question is, why is it that potential energy is minimum when at equilibrium seperation? Why not kinetic energy is minimum since at equilibrium, attractive force = repulsive force and the 2 particle is not moving?