0
$\begingroup$

Imagine that we have two small orbs, one of which is positively charged with charge Q.
These orbs are placed at some distance R.

Will the Coulomb's Law work in this scenerio, even though only one of them is charged? Thus, will the charged orb attract the uncharged one with force $$F=k\frac{Q^2}{R^2}$$

$\endgroup$
1
$\begingroup$

Neutral objects are to charged objects due to an induced charge separation. If the objects are "point objects" as per the title of you question rather than just "small" then there is no room for this induced charge separation and you can not use Coulombs's law to predict an attraction.

$\endgroup$
  • $\begingroup$ What if these objects were very small, would it then be possible to apply Coulomb's Law? $\endgroup$ – ILoveChess Nov 29 '16 at 20:23
  • $\begingroup$ Very small like dust particles - sure. How small are you thinking? $\endgroup$ – M. Enns Nov 29 '16 at 20:26
  • $\begingroup$ Does it work for bigger objects - just like balloons - as well? Another thing - this is quite counterintutitive why the uncharged object is treated as if it had a charge equal to the second object (Q^2) $\endgroup$ – ILoveChess Nov 29 '16 at 20:28
  • $\begingroup$ I've amended my answer to include your balloon question. $\endgroup$ – M. Enns Nov 29 '16 at 20:47
  • $\begingroup$ An important point is missing from this answer: the force due to polarization of the object does not obey Coulomb's Law. So the answer to the OP's question is no. $\endgroup$ – garyp Nov 29 '16 at 21:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.