(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I'm having some problems solving this RLC circuit, if anyone could help.

R = 2 ohms

C = 2/3 F

L = 1/2 H

The top picture is when t < 0

The bottom picture is when t > 0

Find [tex]v_o(t)[/tex] (notice V_0 is the defined +- voltage over the resistor)

http://img503.imageshack.us/img503/448/rlcwo0.th.png [Broken]

2. Relevant equations

3. The attempt at a solution

Well I found that:

[tex]i_L(0^+) = 2 A[/tex]

[tex]v_c(0^+) = 0[/tex]

[tex]v_o(0^+) = -4 V [/tex]

Which I believe are correct,

I found the general equation to be [tex]v_0(t) = Ae^{-t} + Be^{-3t}[/tex]

(My main problem is finding A and B, they should be 2 and -6 but I just can't get that)

A + B = -4

[tex]dv(0^+)/dt = -A + -3B[/tex]

This is where I get a little sketchy, but since Cdv/dt = i_c then I was thinking that since [tex]i_L(0^+) = i_C(0^+)[/tex] for series circuits I could just say

[tex]-A + -3B = 2/C[/tex]

However when I solve those two equations I get A = -4.5, B = 1/2

Does anyone know what I did wrong?

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# Homework Help: Series RLC

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