When a capacitor has a charge of absolute value 80 µC on each plate the potential difference across the plates is 10 V. How much energy is stored in this capacitor when the potential difference across its plates is 120 V?

Question

anonymous · Answer

Do you know how to find the capacitance when charge and voltage are given?

anonymous · Answer

Anyway, use q=C*V to find C. Plug it into E=1/2*C*V^2.

anonymous · Answer

are you sure from this laws :D I applied this rules and the answer is wrong :S

anonymous · Answer

0.48 mJ
	58 mJ
	0.12 J
	0.90 GJ
	0.36 J

anonymous · Answer

@pully, are these the options?

anonymous · Answer

yes

anonymous · Answer

when i followed @arcticf0x's method, i got 57.6 mJ

anonymous · Answer

I got 5.76x10^10

anonymous · Answer

so it will be 58 mj

anonymous · Answer

yes

anonymous · Answer

thnx :)

anonymous · Answer

http://www.wolframalpha.com/input/?i=1%2F2*%2880*10^%28-6%29%2F10%29*120^%282%29

anonymous · Answer

thnx :)

anonymous · Answer

i don't understand the answer i have the same question

anonymous · Answer

Apply this Ahmed q=C*V to find C. Plug it into E=1/2*C*V^2. Then you will get 57.6 mJ