# charge of capacitor

Discussion in 'Homework Help' started by robat davies, Mar 4, 2015.

1. ### robat davies Thread Starter New Member

Mar 4, 2015
6
1
A 10000 microfarads capacitor is charged to 15v and then discharged through a 0.80 Mega ohm resistor. what is the charge 5.0 s after the discharge starts. Thanks

2. ### #12 Expert

Nov 30, 2010
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9,319
dVcap = Dvin log e^(-t/RC)

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3. ### robat davies Thread Starter New Member

Mar 4, 2015
6
1
Thanks again!!

4. ### WBahn Moderator

Mar 31, 2012
20,267
5,766
You need to start showing YOUR attempt to solve YOUR homework problem. Otherwise you aren't going to learn the material and will be in trouble when you can't ask someone else to give you just the formula you need for each problem on your next exam.

5. ### #12 Expert

Nov 30, 2010
17,899
9,319
I handed him the formula because I don't think he can derive this by himself. Besides, it's probably in his text book, so that's where he should look instead of running here every time he needs to look something up.

6. ### WBahn Moderator

Mar 31, 2012
20,267
5,766
Oh, I don't have any heartache with what you did. I'm just concerned that he is developing some bad habits that are going to come back and bite him.

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7. ### #12 Expert

Nov 30, 2010
17,899
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As a person that learned this before the internet was invented, I know the difficulty of having to work alone and teach yourself. The internet probably won't disappear, but a good student surpasses his teachers. The day will come when the internet doesn't have the answer.

8. ### robat davies Thread Starter New Member

Mar 4, 2015
6
1
I thank you for your help, and I have been to see my Physics Teacher today and I got an after school lesson to go over the part of this subject that I missed out on. I only asked for help because I was stuck on this one question because I did not receive the papers for this equation since I was not in the last lesson.

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9. ### #12 Expert

Nov 30, 2010
17,899
9,319
I'm happy you aren't becoming dependent on random strangers. Someday you will fly alone and you need to develop that self-sufficient attitude.