Free electrons in an accelerated metal?

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Discussion Overview

The discussion revolves around the behavior of free electrons in a metal when subjected to external forces, particularly in the context of acceleration and the influence of nearby charges. Participants explore concepts related to electron movement, potential differences, and effects during impacts, touching on both theoretical and practical implications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes how free electrons in a conductor are repelled by a nearby negative charge and suggests that accelerating the metal may cause the electrons to "slosh" to one side, similar to water in a moving container.
  • Another participant notes that the extent of this "slosh" would depend on the mass of the electron and the acceleration, balanced against repulsive forces among the electrons.
  • A participant questions whether a measurable electrical potential occurs between the top and bottom of a metal cube when it strikes the ground, suggesting it might not be significant.
  • References are made to the Stewart-Tolman effect, indicating a potential connection to the discussion of electron behavior under acceleration.
  • One participant asserts that during free fall, electrons and ions accelerate together, implying no relative motion that would generate a voltage difference.
  • Another participant counters that upon impact, the electrons may take longer to reduce their momentum compared to the metal, potentially creating a small voltage pulse.
  • Questions are raised about the behavior of electrons in atomic orbitals under acceleration, with some participants engaging in a playful exchange regarding the terminology used.

Areas of Agreement / Disagreement

Participants express differing views on whether a measurable voltage occurs during impacts and the behavior of electrons in accelerated metals. The discussion remains unresolved with multiple competing perspectives on the effects of acceleration on free electrons.

Contextual Notes

Some claims depend on assumptions about electron behavior in fields and forces, and the discussion includes references to effects that may not be fully explored or defined within the thread.

M de L
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TL;DR
What happens to free electrons in an accelerated metal?
I take a conductor and expose one side to a nearby region of negative charge. The metal's free electrons are repelled, and many collect at the opposite side to the charged region. High School stuff.

Okay, so now I accelerate the metal in one direction. What happens to the free electrons...do they slosh up against the side of the metal, the same way water does in an accelerated bottle?
 
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Welcome to PF.
The amount of 'slosh' in the free electrons will be determined by the mass of an electron multiplied by the acceleration, which is a force; balanced by the repulsive forces between the distributed free electrons.
 
...so I drop a cube of metal, and for the brief moment when it strikes the ground, there is an electrical potential measurable between the top and bottom sides? Prolly not a large one, I imagine?
 
When you hammer in a nail, free electrons move towards the point of impact where the hammer hits the nail.
 
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M de L said:
...so I drop a cube of metal, and for the brief moment when it strikes the ground, there is an electrical potential measurable between the top and bottom sides?
No, because the electrons and ions accelerate together. Neither has to pull or push the other.
 
Okay, so I conduct away all the free electrons in a cube of metal, by hammering it against an earth. My conductor is now an insulator. What happens then?
 
Vanadium 50 said:
No, because the electrons and ions accelerate together. Neither has to pull or push the other.
That is true during the fall, but on impact the metal stops due to bond forces, while the free electrons take slightly longer to reduce their momentum, so they produce a small voltage pulse, negative at the bottom, positive at the top.
 
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M de L said:
Summary:: What happens to free electrons in an accelerated metal?

I take a conductor and expose one side to a nearby region of negative charge. The metal's free electrons are repelled, and many collect at the opposite side to the charged region. High School stuff.

Okay, so now I accelerate the metal in one direction. What happens to the free electrons...do they slosh up against the side of the metal, the same way water does in an accelerated bottle?
What happens to the electrons that are in orbit, does the orbit shift and become closer to the front of the accelerated object?
 
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paradisePhysicist said:
What happens to the electrons that are in orbit, does the orbit shift and become closer to the front of the accelerated object?
What orbit? Low Earth orbit?
 
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  • #11
berkeman said:
What orbit? Low Earth orbit?
I mean the electrons in the orbital, the electron shell.
 
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Lord Jestocost said:
It's called the Stewart-Tolman effect: https://en.wikipedia.org/wiki/Stewart–Tolman_effect
Thank you for a most interesting paper. I noticed that the ballistic galvanometer used could detect a charge in the order of 10^-8 Coulombs, an extraordinary feat.
 
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