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ongxom
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Homework Statement
R=50Ω
L=5H
C=1/125F
vs=200.[1+u(t)] V
Find i(t)
Homework Equations
The Attempt at a Solution
Write the KCL equation
-vs+Ri+L.i'+1/C.∫idt=0
Do the derivation to get rid of the integral, replace all possibly values, we got:
i''+10i'+25i=1/5.vs' (*)
solve A(s)=s2+10s+25=0, we got the natural response in(t)=A1+A2.e-5t
Replace the inductor with a short circuit, the capacitor with open circuit, so I have ip=0
and the initial condition i(0+)=i(0-)=0. (**)
So the solution should be i(t)=in+ip
I thought I was wrong at (**) and maybe at (*) cause the vs' would be zero and the solution would be zero as well.