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Homework Help: Are calories actually burned?

  1. Apr 13, 2006 #1
    What really is a calorie?
    Are calories actually burned?
    Why is this terminology used?
    What are the relationship among a calorie to measure food energy, a calorie to measure heat?
     
    Last edited: Apr 13, 2006
  2. jcsd
  3. Apr 13, 2006 #2

    DaveC426913

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    Gold Member

    A calorie is a unit of energy. 1 calorie of energy will raise 1 gram of water 1 degree C.

    Calories aren't burned, but chemical processes usually involve oxidation, which is a slow burn, which is what is measured by the calorie.

    The food calorie is actually a KCal. (the amount of energy to raise 1 kg of water by 1 degree) i.e. 1 food calorie is equivalent to 1000 calories.

    These days, in the science world (though not in the nutrition world) the calorie is deprecated. The Joule is more common usage. 1 calorie is 4.185 Joules.
     
    Last edited: Apr 13, 2006
  4. Apr 13, 2006 #3
    According to Google calculator 1 calorie = 1/0.239005736 Joule which would make it closer to 4.184 (4,18400000...) Joules.
     
  5. Apr 13, 2006 #4

    Astronuc

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    Getting nitpicky (:biggrin: ) -

    - http://physics.nist.gov/Pubs/SP811/footnotes.html#f11

    http://physics.nist.gov/Pubs/SP811/appenB9.html#HEAT - conversions for units of heat (energy)
     
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