If the line on a distance-versus-time graph and the line on a speed-versus-time graph are both straight lines going through the origin, can the two graphs be displaying the motion of the same object? Explain.

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.