How much energy is stored on a 23-μ F capacitor that is charged to a potential difference of 40 Volts?

Question

jamesj · Answer

The energy in a capacitor is given by
$$ U = \frac{1}{2}QV = \frac{1}{2}CV^2 $$  Now you have C and V, so you have your answer.

jamesj · Answer

U is the energy.  C is the capacitance.  V is the voltage.  Just make sure you put C and V in SI units.

anonymous · Answer

to get it to F from the u-F is the constant10^6?

jamesj · Answer

micro Farad.  Not mega Farad!

jamesj · Answer

so 10^-6

anonymous · Answer

oh whoops! thanks!

anonymous · Answer

I still am not getting the correct answer I am doing (23*10^-6)*40^2*.5

jamesj · Answer

That's 0.0184 J.  

What's the supposed answer?

anonymous · Answer

It is saying J isnt the right units

anonymous · Answer

Nevermind I wasnt typing it in correctly i was using 1.84*10^2 instead of -2

jamesj · Answer

Good