More RLC Troubles: How the Resistor Disappears

[NewtonianAlch]

Homework Statement

http://img69.imageshack.us/img69/1123/85049619.jpg


Got a nasty surprise after finishing the problem and looking at the solutions to see the resistor disappearing at tax time.

I can't figure out how the resistor disappears, I can only think the people who solved this were looking at a different circuit of sorts.

 

[berkeman]

Homework Statement

http://img69.imageshack.us/img69/1123/85049619.jpg


Got a nasty surprise after finishing the problem and looking at the solutions to see the resistor disappearing at tax time.

I can't figure out how the resistor disappears, I can only think the people who solved this were looking at a different circuit of sorts.

The voltage source is a short circuit (if it's an ideal voltage source), and it's in parallel with the resistor...

 

[vela]

It would have been better if the solutions didn't say the LC circuit was disconnected from the voltage source. It's not. The voltage source has to still be there to ensure no current flows through the resistor.