What is the potential difference between the plates?

AI Thread Summary
The discussion revolves around calculating the potential difference and work related to a parallel-plate air capacitor with a capacitance of 730 picoFarads and a charge of 2.95 microCoulombs. The initial attempt to find the potential difference using the formula V=Q/C resulted in an incorrect value, but after recalculating, the correct voltage was determined to be approximately 4041.1 volts. When the separation between the plates is tripled, the new potential difference is calculated to be 12123.3 volts, which is three times the original voltage. To find the work required to triple the separation, the equation U=1/2 Q V is applied, with the change in energy calculated as the difference between the final and initial energy states. The discussion highlights the importance of accurate calculations and the application of relevant formulas in solving capacitor-related problems.
eku_girl83
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Here's my problem:
A parallel-plate air capacitor has a capacitance of 730 picoFarads. The charge on each plate is 2.95 microCoulombs.
a) What is the potential difference between the plates? I used the equation V=Q/C to get 2.4746E-4 V, but this is incorrect.
b)If the charge is kept constant, what will be the potential difference between the plates if the separation is tripled?
I think it would be divided by three.
c) How much work is required to triple the separation?
U=1/2 Q V

I think if I could calculate the potential difference correctly, I could work the rest of the problem. Any hints/help would be welcome!
 
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Check your arithmetic, I do not get the result you posted using the same equation and numbers. Post your calculation.
 
I punched the numbers into the calculator wrong! I now get the voltage equal to 4041.1
Tripling the distance produces a voltage of 3V or 12123.3
Now, how do I apply the equation U=1/2 Q V to find the work required to triple the separation?
 
it would be Uf-Ui=W
 
Thank you! You are all so helpful :)
 
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