Where does an electron's kinetic energy go?

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Discussion Overview

The discussion centers around the fate of an electron's kinetic energy as it moves through a wire in a circuit, particularly after it reaches the terminal of a battery. Participants explore various aspects of energy conversion, including potential energy, kinetic energy, and heat, as well as the role of electrons in chemical bonding.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions where the kinetic energy of an electron goes after it reaches the terminal, suggesting some is converted to heat.
  • Another participant proposes that kinetic energy may also contribute to the formation of chemical bonds when electrons attach to atoms.
  • A participant argues that electrons are light and their kinetic energy is negligible except in high-energy contexts like particle accelerators.
  • In response, another participant corrects this view, stating that while drift velocity is low, electrons in a conductor have random velocities that can be significant, and some kinetic energy is converted to heat through interactions.
  • One participant expresses skepticism about the relevance of kinetic energy in the context of energy delivered by the circuit, comparing it to the kinetic energy of weights in a grandfather clock.

Areas of Agreement / Disagreement

Participants express differing views on the significance of kinetic energy in circuits, with some emphasizing its negligible role while others argue for its importance in energy conversion processes. The discussion remains unresolved regarding the exact contributions of kinetic energy in this context.

Contextual Notes

There are limitations in the assumptions made about the velocities of electrons and the definitions of kinetic energy in relation to circuit energy delivery. The discussion does not resolve these complexities.

LightningB0LT
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When an electron moves through a wire between two terminals on a battery some of its potential energy is converted to kinetic energy. My question is, where does that kinetic energy go once it reaches the other terminal? Some of it is probably converted to heat, but what about the rest of it?
 
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hw about in the chemical bond that it makes when its attached to an atom?
 
Electrons are very light and move at a rather slow velocity. Their kinetic energy is completely negligible unless your application is a particle accelerator.
 
mrspeedybob said:
Electrons are very light and move at a rather slow velocity. Their kinetic energy is completely negligible unless your application is a particle accelerator.

Absolutely incorrect. In a room temperature conductor electrons have random velocities which are a significant fraction of c. What is low is the DRIFT velocity imposed but the EMF of a circuit.

Some Kinetic energy is converted to heat due to interactions with other electrons and the crystal structure.
 
Yes. I was referring to drift velocity. Thank you for the correction.

I am dubious however about the contribution of kinetic energy to the energy delivered by the circuit, including the energy converted to heat. The energy delivered by the circuit is the energy of electrons moving from higher potential to lower potential.

Talking about the kinetic energy of electrons in a circuit seems to me like talking about the kinetic energy of the weights that power a grandfather clock. Yes, they do move but it's a stretch to say the clock is powered by their kinetic energy.
 

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