Re: Why does electrostatic attraction in water decrease?

[Pentcho Valev <pvalev@BAS.BG>]

"John S. Denker" wrote:

> Pentcho Valev wrote:
> > I cannot do the experiment, for many reasons.
>
> Really?  What reasons?  How hard did you try?

Sometimes life conditions are unfavorable.

> > However there is another instructive
> > thought experiment
> ....
> > A) The net work gained in steps 1 and 3 is done at the expense of heat absorbed from
> > the surroundings. If so, the second law is of course violated.
>
> I see no reason to believe this would happen.
>
> > B) The net work gained in steps 1 and 3 is done at the expense of WORK THE OPERATOR
> > SPENDS IN STEPS 2 and 4. This saves the second law, but is somewhat
> > counterintuitive.
>
> It seems perfectly intuitive to me.
>
> > Roughly speaking, this means that in step 4, as the operator lifts
> > the capacitor, the capacitor is MUCH HEAVIER than in step 2 when the operator lets
> > it down.
>
> Not "MUCH" heavier, just heavier enough.
>
> Elementary electrostatics predicts exactly this.
> You can do the calculation on a 2-inch square piece of
> paper;  why not do it yourself?

Which force do you think pulls the capacitor downwards in step 4 but does not pull it in
step 2?