Understanding Coulomb's Law: What if One Object has No Charge?

[Cyrus]

Im reading Coulmbs law and I have stumbeled upon a problem. The numerator is the product of the two charges. But according to inductance, I can create a force of attraction between two objects if only one object has a charge. So charge two would be zero? And the force would be zero!? That does not make sense, would the proper thing be to break the charge equally in half between the two objects? or should I consider the force to be the same for each object as the charged one?

 

[Tide]

Inductance will give you a distribution of charge even if the net charge is zero. That means, for example, that some of the redistributed charge of one sign will be closer to the external charge than the oppositely signed charge - so attractive and repulsive forces won't exactly cancel.

 

[Cyrus]

So then for q1 * q2, I would effectively use the same number as the charged object and assume the uncharged object has picked up the same charge value?

 

[Tide]

Yes, but you would have to do that for every element of charge dq throughout the volume of the object. Incidentally, finding the actual charge distribution is not trivial except in very special cases!

 

[Cyrus]

Hey Tide, what's all this junk in my book. i think there trying to explain something to me, imagine that, but i don't get it.

"we conclude that in electrostatics the electric field at every point within the material of a conductor must be zero. (Note that we are not saying that the field is necessarily zero in a hole inside a conductor)."

what in the world do they mean by that?