Using Laplace to solve circuit analysis

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The discussion focuses on using the Laplace transform for circuit analysis, highlighting the correct representation of a DC source as V/s, specifically noting a 12 V source as 12/s. The participant expresses uncertainty about the general procedure for solving these problems, indicating a mistake in their calculations despite having the correct exponential term. It is emphasized that the voltage representing stored energy from an initial current must accurately reflect its polarity. Overall, the conversation aims to clarify the application of Laplace transforms in circuit analysis.
Cocoleia
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Homework Statement


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The Attempt at a Solution


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As you can see, the answer is given in the problem. I have the 0.8t par right but somewhere along the way I messed up. I'm not really to sure about how to solve these types of problems using Laplace. Is there a general procedure that I should be following that I am not?
 
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The Laplace transform of a DC source is V/s. Essentially it's modeled as a step function, "turning on" at time t = 0. So your 12 V source should be 12/s.

The voltage that represents the stored energy due to the initial current (your 30 V supply) needs to have its polarity reflect the actual direction of that initial current.

Otherwise you seem to be doing okay.
 
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