What Is the Force Between Plates of a Parallel-Plate Capacitor?

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The discussion focuses on calculating the force between plates of a parallel-plate capacitor, the work required to double the distance between the plates, and the effect on voltage when the distance is increased. The user expresses confusion about how to start solving the problem and considers using Coulomb's Law but finds it unhelpful. Key equations provided include the capacitance formula and relationships between charge, area, and electric field. The user seeks assistance in understanding these concepts and their interconnections. The thread highlights the challenges of applying theoretical equations to practical problems in electrostatics.
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Homework Statement



Imagine you have a parallel-plate capacitor with area A and charge Q = \sigmaA, separated by a distance x, which may vary while the charge stays fixed in the plates.

a. The force that each plate exerts over the other can be expressed as _______.
b. How much work is required double the distance that the plates had between them originally?
c. If the original voltage is V, once the distance between the plates is doubled, the voltage between the plates will be _________.

Homework Equations



C = (ε0 A)/d

E = σ/A

σ= Q/A


The Attempt at a Solution



I really don't know where to start this one. Since it asked for force I thought about using Coulomb's Law but that took me nowhere. I'm guessing the equations I put above are vital in all of this, but I can't seem to figure the relationships out. Any help at all would be appreciated. Thanks.
 
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Thanks. I'll check that out then.
 

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