Effect of the magnetic field on a charged object's inertia.

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Discussion Overview

The discussion revolves around the effect of magnetic fields on the inertia of charged objects, particularly focusing on the implications of magnetic fields on the kinetic energy of electrons when accelerated by electric fields. The scope includes theoretical considerations and conceptual clarifications regarding inertia and energy storage in magnetic fields.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested
  • Historical

Main Points Raised

  • One participant questions whether the energy used to accelerate an electron is partially stored in its magnetic field, suggesting this could affect its final velocity.
  • Another participant clarifies that while energy may be stored in the magnetic field, it does not change the inertia of the object, only its kinetic energy.
  • A different participant challenges the idea that a magnetic field of a single particle can store energy, suggesting that the concept may relate more to induction.
  • One participant expresses a desire for another to explore the calculations involved in determining the energy effects.
  • Historical context is provided by referencing past considerations of electromagnetic mass, indicating that these ideas have been discussed for over a century.
  • A later reply notes that in semi-classical models of semiconductor transport, electrons are treated as having an effective mass that differs from their rest mass.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between magnetic fields and energy storage, with some supporting the idea that magnetic fields influence kinetic energy while others dispute this notion. The discussion remains unresolved regarding the implications for inertia and energy storage.

Contextual Notes

There are limitations in the assumptions made about energy storage in magnetic fields and the definitions of inertia and effective mass. The discussion does not resolve these complexities.

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A question many of us repeatedly solved in high school goes like this: An electron is accellerated a certain distance by an electric field of a certain strength. Determine its final velocity.

I and my teachers always treated this as a simple F=ma question, but recently it's occurred to me that a moving charge has a magnetic field, and magnetic fields store energy. Does that mean the electron would end up moving more slowly because some of the energy that goes into the electron goes into the magnetic field? Does this mean the electron has an "inertia" mass higher than its "gravity charge" mass?
 
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You are saying that some of the energy that may otherwise have gone into the motion of the charge gets stored in it's magnetic field?

This does not change the inertia of the object though, just it's kinetic energy.
Have a go working out how big the effect is.
 
I don't believe that magnetic field of a single particle can store energy. I think you are referring to the effect of induction, which is different.
 
Of course in the semi-classical model of transport in a semiconductor, an electron is treated as having an effective mass different from it's rest mass.
 

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