Electric Potential and a capacitor

[Jodi]

Hi; Could someone please help me with the following question: A huge 4.0 F capacitor has enough stored energy to heat 2.5 kg of water form 21 degrees celsius to 95 degrees celsius. What is the potential difference across the plates? Could i use the equation: PE = 1/2 CV^2. However, I do not know how to solve for PE; how do I use the given temperatures and mass? Thank you for your help.

 

[karen03grae]

I would use q=m*c*delta(T) to get the heat (Joules) transferred by the capacitor. m=the mass in grams of your water. c is the specific heat of water. delta T is the change in temperature. Then set that amount equal to your potential energy and solve for V...I think that's right

 

[Jodi]

thanks

Thanks a lot for your help, I understand it now.