Monday

July 28, 2014

July 28, 2014

Posted by **J** on Monday, February 4, 2008 at 5:56pm.

I am totally confused I don't even know where to start. Help please!

- Physics -
**Damon**, Monday, February 4, 2008 at 6:16pmGee, I guess I better figure out how much energy is stored in a capacitor at voltage Vf and capacitance C

C = q/V

q = V C

dq/dt = i = C dV/dt

power = i V

power = C V dV/dt

so

power dt = C V dV

integral power dt = Energy = C integral V dV from V = 0 to V = Vf

but integral of x dx = (1/2)x^2 + constant

so

Energy at Vf = (1/2)C Vf^2

ok, now we can use that

Energy = (1/2)(450*10^-6)(295)^2

or

19.6 Joules

**Related Questions**

physics - A parallel-plate capacitor has plates with an area of 450 cm^2 and an ...

PHYSICS - A parallel-plate capacitor has plates with an area of 450 cm^2 and an ...

Physics - A capacitor has two overlapping plates of width 4.9 m and length 3.5 m...

Physics - When an air capacitor with a capacitance of 380 nF (1 {\rm nF} = 10^{-...

Physics - When an air capacitor with a capacitance of 300 nF (1 {\rm nF} = 10^{-...

pjysics - A capacitor that has 10 cm diameter plates, 0.1mm apart, is charged at...

Physics - Find the electric field between the plates of a capacitor given the ...

College physics - Open Question: Find the electric field between the plates of a...

Physics - A certain parallel capacitor consist of two identical aluminium plates...

Physics - A parallel-plate capacitor has a capacitance of 2.1 µF with air ...