Second order frequency response question

[Learnphysics]

Homework Statement

http://img534.imageshack.us/img534/9687/rlc.png

Cannot do this question, the first part confuses me when it asks to find an equivalent Parallel circuit.

My first instinct was to try to add the capacitor and inductor and 40k Resistance together to create an RLC series circuit.

From this to add the 40k and the 10k resistances (because they are now in series)... Then we have a circuit with one resistance and one component causing impedance.

From here if we could SPLIT the impedance into both capacitance and inductance, we would have a parallel RLC.



how to mathamatically do the last part (the splitting of a given impedance into a parallel capacitance and inductance) I have no idea.

Or is there a much more simple/elegant way to go about doing this?

 

[viscousflow]

Have you tried Thevenin equivalent?

 

[jegues]

Homework Statement

Cannot do this question, the first part confuses me when it asks to find an equivalent Parallel circuit.

My first instinct was to try to add the capacitor and inductor and 40k Resistance together to create an RLC series circuit.

From this to add the 40k and the 10k resistances (because they are now in series)... Then we have a circuit with one resistance and one component causing impedance.

From here if we could SPLIT the impedance into both capacitance and inductance, we would have a parallel RLC.
how to mathamatically do the last part (the splitting of a given impedance into a parallel capacitance and inductance) I have no idea.

Or is there a much more simple/elegant way to go about doing this?

I'm not 100% sure about this but couldn't you simply find the Norton equivalent at the terminals of the inductor?

Then you would have a parallel RLC circuit with a current source supplying power as opposed to a voltage source.