Does Eddy Current Braking Violate the Conservation of Energy?

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Discussion Overview

The discussion revolves around the mechanics of eddy current braking, specifically addressing the conservation of energy in the context of a roller coaster slowing down. Participants explore how kinetic and potential energy are transformed during the braking process and whether all energy lost is converted into thermal energy.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether the conservation of energy can be applied in the case of eddy current braking, specifically asking if the energy transformations can be expressed as E kin + E pot -> E' kin + E' pot + E' therm.
  • Another participant asserts that the kinetic energy is converted into heat during the braking process.
  • A participant seeks clarification on whether both the initial kinetic energy and the energy involved in the braking procedure are transformed into heat.
  • One participant explains that eddy currents are generated when a conductor moves in a magnetic field, converting the rotational energy of the wheels into eddy currents, which dissipate due to electrical resistance.
  • It is noted that the kinetic energy decreases due to friction between the wheel and the track, and that the energy lost is equal to the heat produced from eddy currents and friction.
  • A participant questions whether the absence of friction implies that all energy is converted into heat, and challenges a previous assertion regarding the treatment of potential energy in the context of a roller coaster.

Areas of Agreement / Disagreement

Participants express differing views on the specifics of energy transformation during eddy current braking, particularly regarding the roles of kinetic and potential energy. There is no consensus on whether all energy is converted into heat or how potential energy is accounted for in the process.

Contextual Notes

Participants have not reached a resolution on the assumptions regarding energy transformations, particularly in the context of potential energy and the role of friction in the braking process.

Gavroy
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Hey,
I have one question about the eddy current brake, or electromagnetic induction at all. For instance, slowing a roller coaster from let me say 40m/s to 10m/s in 20m by a eddy current brake(THIS IS NO HOMEWORK!). What is about the conservation of energy in this case. can you say that E kin + Epot->E' kin + E' pot + E' therm or is this wrong? Is it valid to use the conservation of energy in this case at all? I am not sure! How do you think about this problem? I am not even sure, whether all the energy lost by the slowing down procedure goes into thermal energy?

sry about my english, but I do not live in a english-speaking country...:smile:
 
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The kinetic energy is turned into heat.
 
So you would say that the kinetic energy of the roller coaster at the beginning is turned into heat and the potential energy is turned into kinetic energy, electric potential energy and the potential energy at the end?

I just want to be sure that I understand you right!
 
Last edited:
or can somebody explain me more precisely which kinetic energy is transformed into heat. the initial kinetic energy or also energy of the brake procedure?
 
can nobody help me with my problem? :frown:
 
Eddy Currents are generated when something conducting moves in a Magnetic field. The brake converts the rotational energy of the wheels into eddy currents and these currents are dissipated because of electrical resistances in the conductor.
The kinetic energy deceases because of friction between the wheel and the track.If the brakes are sufficiently weak rolling will be maintained else the system will try to slide.
The kinetic and rotational energy lost will be equal to the heat lost from eddy current and friction.
 
okay thanks a lot, so if there is no friction then all energy is turned into heat. does this mean that antiphon was wrong, when he said that just kinetic energy is turned into heat or what happens to the potential energy, since I was talking about a roller coaster, which has also potential energy?
 

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