## Question regarding Coulomb's Law

 Quote by ehild Well, there can be some thin water layer on the surfaces, and it can conduct electricity quite well because of the ions dissolved in it. In my experiments, the paper pieces sometimes stay attached to the comb quite long, but the air is usually dry here. It can be different at your place :) ehild
oh but when they touch, after a while some electrons from the plastic will enter the metal. As a result of this the other electrons on the end of the metal will start to spread out more as well due to the smaller repulsion forces acting on them (which initially pushed them to the end) and also because of the repulsion between themselves? So because of that, bit by bit the repulsion will become stronger than the attraction which causes them to fall off?

But actually i am unable to picture how the forces will act on the metal. The force acts on the electrons so how would that enable the whole object to accelerate? And also for the nucleus a force is acting on it but unlike the electrons they don't move. I can't seem to resolve this issue and it's causing some confusion.

Thanks for the help :)

Recognitions:
Homework Help
 Quote by sgstudent But actually i am unable to picture how the forces will act on the metal. The force acts on the electrons so how would that enable the whole object to accelerate? And also for the nucleus a force is acting on it but unlike the electrons they don't move. I can't seem to resolve this issue and it's causing some confusion. Thanks for the help :)
The metal rod consists of its ions and electrons. The ions are arranged in a certain way and can not leave their position. The electrons are free to move inside the metal but can not leave the metal.
The external charge brought close to the metal rod acts on all constituents, both ions and electrons. Also all particles of the metal interact with each other. Every particle feels a force from the external charge (external force) and forces of interaction from the other particles. The interaction forces keep the ions and electrons together and make the metal move as a single body. The sum of all external forces determine the acceleration of the rod as whole.
The external negative charge attracts the ions and repels the electrons. That force of repulsion is a bit smaller than the attraction as the electrons are accumulated in the farther part of the rod. So the net force on the rod as whole is attractive.

Discussion like that would be better on the forum "General Physics". This is not homework.

ehild