## Jonask 2 years ago work done to move a capacitor in parrallel a distance x

1. yrelhan4

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|dw:1364587708013:dw|

3. yrelhan4

I was just tagging myself.

herre i mean to move it away from the other by applying a force $F_A$

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6. electrokid

work done = change in internal energy

7. electrokid

1) Energy in a capacitor $$U={1\over2}{Q^2\over C}$$

F=qE

9. electrokid

2) what changes when you separate the plates? capacitance: $C={\epsilon_0kA\over d}$

10. electrokid

so, $U={1\over2}{Q^2d\over\epsilon_0kA}$

11. electrokid

W = final energy - initial energy

12. electrokid

remember that Q does not change in this case, but C and V do

13. electrokid

@Jonask you are increasing the separation between the plates, right?

yes i was hoping for $dW=Fdx$

i dont see x in you expressions above

i would like us to do it intergration way