Circuits: Draw Equivalent Resistance

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The discussion focuses on simplifying a circuit to find the equivalent resistance. The user is confused about how to relate the resistances R_1, R_{(3||4)+5}, and R_2. The solution involves combining R_{(3||4)+5} with R_2 in parallel, as they share the same connection points after current leaves R_1. Clarification is provided that the resistors are indeed in parallel since their leads connect together, allowing current to split between them. Understanding these connections is crucial for correctly calculating the equivalent resistance.
Saladsamurai
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Homework Statement



Man, I stink at circuits. I have to simplify the 1st circuit in the image below to an equivalent resistance. I am almost there, but I am unsure of how to relate the remaining 3 resistances. In the drawing, a subscript Ri||j denotes the equivalent resistance of the two parallel resistors i and j; similarly, Ri+j is the equivalent resistance of the two series resistors i and j.

Now, I am not sure how to relate R_1,\,R_{(3||4)+5},\,R_2 and I think my confusion lies in the fact that I do not know what is going on with the current in this last circuit. Can someone help me out with that?

Screenshot2011-01-22at121832PM.png
 
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You have it pretty well finished! Just combine the R(3||4)+5 with the R2 in parallel. That result is in series with R1.
 
Delphi51 said:
You have it pretty well finished! Just combine the R(3||4)+5 with the R2 in parallel. That result is in series with R1.

OK! Now, this is because after the current leaves R1, it splits among R2 and R(3||4)+5 so we combine them in parallel. Right?

Thanks again Delphi!
 
They combine in parallel because they *are* in parallel! Look at how their leads connect.
 
gneill said:
They combine in parallel because they *are* in parallel! Look at how their leads connect.

Hi gneill! I don't understand your reply!
 
I think you are both saying the same thing! Parallel means both ends of the resistors are connected together AND that the current splits between them.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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