why does metal get hot when you bend it?

Discussion in 'Highly Technical' started by theMan, Mar 5, 2009.

  1. theMan

    theMan Diamond Member

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    i was sitting here bending the handle of a fork back and fourth, and it got so hot after about 3 seconds it burned my finger. what causes this heat? friction inside the metal?
     
  2. Brutus04

    Brutus04 Senior member

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    Exactly; The atoms scrape against each other as the metal bends out of it's original shape. It's like rubbing your hands together except on a very smaller and more densely populated scale.
     
  3. blahblah99

    blahblah99 Platinum Member

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    First law of thermodynamics.
     
  4. Born2bwire

    Born2bwire Diamond Member

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    is you don't talk about thermodynamics. :|
     
  5. CycloWizard

    CycloWizard Lifer

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    Input work by bending/stretching and you increase the internal (strain) energy of the fork. Viscous losses in the fork convert the energy to heat, while some of them are stored as elastic strain energy which will recover some of the strain you impart.
     
  6. KIAman

    KIAman Diamond Member

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    Conservation of energy.

    Energy used to bend the fork gets converted into heat.

    Chemical energy from ingested food yields glucose,
    which is converted to ATP,
    which is converted to ADP and release energy,
    which allows release of ionic calcium in the muscle,
    which interact with myofibrils to induce contraction and produce kinetic energy,
    which gets converted to kinetic energy applied to the metal thereby bending it,
    which gets converted to thermal energy in the metal.

    Total efficiency to produce heat from chemical energy through this process... less than 5%?!?
     
  7. BladeVenom

    BladeVenom Lifer

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    In this house, we obey the laws of thermodynamics. :p
     
  8. polarbear6

    polarbear6 Golden Member

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    two words
    tangential stress
    simple mechanics

     
  9. mindless1

    mindless1 Platinum Member

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    Your will caused the heat, friction was only a side-effect. If you keep it up you will be kicked out of our restaurant. :)
     
  10. JTsyo

    JTsyo Lifer

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    There is no fork.
     
  11. Coca Cola

    Coca Cola Member

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    There is no fork?




     
  12. Kraeoss

    Kraeoss Senior member

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    upon concentrating on the fork realise that it's not the fork that bends but you and you burned your self with that realization......
     
  13. Jahee

    Jahee Platinum Member

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    Real helpful..
     
  14. bobsmith1492

    bobsmith1492 Diamond Member

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    That's four words...

    One word:

    Friction