Motional emf, Gaussian flux, and lenz's law help

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Homework Help Overview

The problem involves two bars connected to a battery, with a focus on their motion and interactions when a switch is closed and then opened. It touches on concepts such as motional electromotive force (emf), spring mechanics, and electrical resistance.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to understand the motion of the bars in relation to motional emf and whether they generate a magnetic field or act as capacitors. Questions are raised about the area of the bars and how it relates to the problem.

Discussion Status

Participants are clarifying the problem by requesting a diagram and confirming the details of the setup. Some have noted the equivalent resistance of the bars when connected in parallel, indicating a direction towards understanding the electrical aspects of the problem.

Contextual Notes

There is mention of an equivalent spring constant for the system, and the assumption of no friction is emphasized. The original poster also notes the initial distance between the bars and the conditions under which they operate.

Turpulus
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Homework Statement



Two bars, each 30cm long, and each having a resistance of 2-ohms, are connected to a 1,500 volt battery. The bars are attached to each other with 3 insulating springs, each having a spring constant of 9N/m. The two bars are initially at rest, 4cm apart. The switch is closed, and then opened. Assume no friction anywhere in the system. 1. How far will the two bars be from each other with the switch is closed? 2. After the switch is open, what is the closest the two bars wil get to each other? 3. After the switch is open, what is the farthest the two bars will get from each other? 4. Describe the motion of the two bars at time, t, after the switch is open.

Homework Equations



v ir
Spring constant equations

The Attempt at a Solution



I know motional emf would cause the bars to move apart but they're not passing through a magnetic field. Are they generating a mag field? Are they acting as capacitors and building up repulsive charges? If so, how do you get the area of the bar if you are only given the length? Thanks!
 
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Hi, is there a diagram given ? without the aid of a diagram its difficult to understand.
Always post the question AS IT APPEARS in your textbook or homework...
 
Here is the exact question with diagram:
Two bars, each 30cm long, and each having a resistance of 2.00 ohms, are connected to a 1500V battery. The bars are attached to each other with 3 insulating springs each having a spring constant of 9N/m. The two bars are initially at reast, 4cm apart. The switch is closed, and then opened. Assume there is no friction anywhere in the system. Note: One can define the equivalent srping constant for the system equal to 27N/m. 1. How far will the two bars be from each other with the switch closed? 2. After the switch is open, what is the closest the two bars will get to each other? 3. After the switch is open, what is the farthest the two bars will get from each other. 4. Describe the motion of the two bars at time, t, after the switch is open.


So I realize that the bars are connected in parallel, so the equivalent resistance is 1ohm. I'll post a diagram.
 
Here is the diagram. Thanks!
 

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