Thompson's Absolute Electrometer

[X53]

Suppose that the force needed to push a disc down on top of another disk = weight x g, then the two discs are charged with opposite quantities of electricity, then the weight removed, and still the discs remain together due to the force of attraction between the discs; so then the electric force between them is equal to the force from the weight, right? this implies that Wg = (V^2A)/[(8PI)D^2], V is voltage, A is the area of the top disc, D is the distance between them: How to explain the equation? what is the significance of 8pi?

 

[X53]

Suppose that the force needed to push a disc down on top of another disk = weight x g, then the two discs are charged with opposite quantities of electricity, then the weight removed, and still the discs remain together due to the force of attraction between the discs; so then the electric force between them is equal to the force from the weight, right? this implies that Wg = (V^2A)/[(8PI)D^2], V is voltage, A is the area of the top disc, D is the distance between them: How to explain the equation? what is the significance of 8pi?

Why doesn't anyone answer?