The basics of thermal energy as how it relates to Amperes and Watts

Discussion in 'Physics' started by ZigZag, Aug 16, 2010.

  1. ZigZag

    Thread Starter Member

    Jul 22, 2010
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    I'd like to know if I am understanding correctly that in the example, where a copper rod is bent into a ring and spliced into it are the battery and a light bulb, the light bulb filament is heated by two forces simultaneously:
    [Exhibit A] the friction from the Coulombs and the [Exhibit B] the friction resulting from the electrical energy that forces itself through the flow of Coulombs (which may or may not move against the electrical energy.

    This leads leads me wondering which of the forces create greater friction on their own and if there are instances where only one of the frictional forces are present and not the other.


    Exhibit A: "Make another cut in the metal ring, install a light bulb in the cut, and then the "friction" of the narrow light bulb filament against the flowing charge-stuff creates high temperatures, and the wire filament inside the bulb glows white-hot. The battery drives the ring of charge into motion, the charge moves along like a drive belt, and the light bulb "rubs" against the moving charge, which makes the filament grow hot. " http://amasci.com/elect/vwatt1.html

    Exhibit B:
    "For example, whenever a battery powers a light bulb, the battery spews electrical energy into space! The electrical energy is then grabbed firmly by the wires and guided by them. The energy flows parallel to the wires, and eventually it dives into the light bulb filament. There it drives the metal's charges against the resisting force of electrical "friction," and the electrical energy gets converted into thermal energy. " http://amasci.com/elect/poynt/poynt.html


    I absolutely love William J. Beaty's explinations. I found them more useful that anything I have ever read in many years of atemptiong to study electricity. He provides the only form of information on this complex subject that my mind accepts: the whole picture.


    Thank you guys for your time and effort helping me understand the science behind this amazing subject!
     
  2. ZigZag

    Thread Starter Member

    Jul 22, 2010
    264
    0
    I think this should be in the Physics section, if so, can someone move me there please?
     
  3. davebee

    Well-Known Member

    Oct 22, 2008
    539
    46
    I would say that both of these descriptions are trying to say the same thing.

    Exhibit A is a little closer to physics. Exhibit B is more like poetry than physics.

    A poetic description may be helpful when you're first learning about physics, but you should not think of a poetic explanation as a physics explanation.

    Words like force and heat and energy are defined quite carefully in a physics explanation, and should be used only as they are defined, where words like spews and grabbed and dives are more suitable for poetry; for building a mental picture.

    But your questions are good ones, in physics, even such a simple thing as how a battery heats a light bulb is not an easy thing to correctly explain.
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    A battery is kinda like a balloon. It sits there full of potential energy.

    When you let the fill tube loose on the balloon, the air is released at a rate controlled by anything in front of and connected to the fill tube.

    If you make the tube smaller (add resistance) the air escapes slower.

    If you try to SUCK the air out faster, the fill tube will try to collapse.

    The air molecules squeezing through the resistor will also rub together.

    When they rub together they will trade electrons back and forth with eachother and with the "resistor" material.

    The lightbulb filament changes chemical composition as it heats up, loosing electrons in the process.

    The lost electrons are radiated as heat/light.

    In a balloon you get the nice "squeeking" or "whistling". This is its reaction to the air molecules bouncing all around reacting with the rubber.

    ish.

    ;)
     
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