State Space Model of an RL Circuit

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The discussion revolves around deriving a state-space model for an RL circuit, with the input as v(t) and output as vL(t). The user attempted to solve the problem using two methods: KCL in the time domain and mesh analysis, but obtained differing transfer functions from each approach. This discrepancy raises questions about the accuracy of either the state-space analysis or the mesh analysis. A suggestion was made that a term may have been omitted in the time-domain method, potentially leading to the inconsistency. Clarification on the calculations and assumptions in both methods is sought to resolve the issue.
YoshiMoshi
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Homework Statement



For the given circuits, identify state variables and derive a state-space model for each.
Assume the input is v(t) and the output is vL(t).

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Homework Equations

The Attempt at a Solution


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So my issue is that I solved this problem using two different methods. First method I used was trying to find the state space model directly using KCL in the time domain. I then took my state space model used derived using this method and found the transfer function. I then found the transfer function directly using mesh analysis. For some reason I got two different transfer functions. So that means either my state space analysis from my first method was incorrect, or the second transfer function I found using mesh analysis was incorrect. I'm not exactly sure what I did was incorrect, my transfer function using mesh analysis, or my state space analysis. Any help would be greatly appreciated.
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The form of your answer using the 2nd method looks correct (bandpass filter), but I didn't check the math in detail
upload_2018-10-11_13-36-56.png

But it seems like you dropped a V(t) term in you answer using the first time-domain method? (Or I could be missing something)...
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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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