Answer the question.

Discussion in 'Chemistry' started by Beaconator, Jun 2, 2014.

  1. Motor Daddy Valued Senior Member

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    Then you've said nothing. You've failed to quantify your position and statements!
     
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  3. exchemist Valued Senior Member

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    Perhaps you never learnt (or have chosen, eccentrically, to disbelieve) thermodynamics.

    Energy is (1) neither created nor destroyed, but (2) it most certainly does degrade, in the sense of becoming less available to do work. (1)and (2) are in effect simple expressions of the 1st and 2nd laws of thermodynamics, respectively.

    Whether it starts off as electrical energy, or nuclear energy, or any other kind, it all eventually turns into the lowest grade of energy, which is low temperature heat. That is where your kilowatt-hours have gone: into slightly warming up your house, or the environment, or whatever.

    And once the energy is in that form you can't get it to do anything for you, unless you can find a colder heat sink into which some of it can flow. It's there, but it is to all intents and purposes useless. Which is why we speak of "waste heat".
     
    Last edited: Jun 16, 2014
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  5. Motor Daddy Valued Senior Member

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    The ice cream is in the gas too, but you can't eat it. Why would you think you can eat the ice cream when you can't see it or measure it? That would be ridiculous! It's all there, it's just that it's useless.

    See how that works?

    There's also nails, toothpicks, dimensional lumber, and waste oil in the gallon of gas, but as usual, just like invisible green monsters in the backyard (and in the gas too), you can't see 'em, and they aren't measurable, but they're ALL THERE! Trust me.

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  7. Motor Daddy Valued Senior Member

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    Are you saying that the 1 kw-hr of energy consumed from the 10 hours of operating the 100 Watt light bulb is less available to do work after the 10 hours is complete? So there's what, approximately .5 kw-hr of energy available to do work after the light bulb operates for 10 hours?
     
  8. exchemist Valued Senior Member

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    12,451
    No. It's not available at all, unless you can find somewhere cooler for the heat to flow to.

    Heat is the lowest (=least useful) form of energy, and low temperature heat is the lowest of the low. That's what the 2nd Law tells us.
     
  9. Motor Daddy Valued Senior Member

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    5,425
    So it's not available at all now? It's not just degraded and less available like you claimed before, now it's not available at all!

    So a gallon of gas has energy that's not available at all. It's all in the gas, although you can't measure it or see it, but it's all there! Just not available.

    Got it!

    You think the reason it's not available at all is that it's spread out too much?
     
  10. billvon Valued Senior Member

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    21,634
    Without a lower temperature heat sink - that is correct. It's not available at all. As a simple example, if you operate a light bulb in a house, and then turn it off, that energy is no longer available. It has been transferred to the ambient environment, thus heating it up a fraction of a degree. It is, from the point of view of USEFUL energy, gone.

    It is not available as useful energy. It is still there as heat, specifically a tiny increase in ambient temperature.

    Depends on its temperature and the relationship of that temperature to ambient. In the previous example (room temperature gas, presumably in a room) then the thermal energy is there but not available. You can measure the available useful energy only in relation to some other heat sink or source.
     
  11. Motor Daddy Valued Senior Member

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    Again you fail to realize what energy is. Do you happen to know that a unit of power is a Watt, as in "100 Watt light bulb"? Do you happen to know that energy=power*time? Would you say it's fair to say that if you turn on the 100 Watt light bulb at 1PM, and it stays on until 11PM, that the light was on for 10 hours??? So the test is over at 11PM. The results are final. The energy was 1,000 Watt-Hours (100 Watts times 10 hours).

    Why do people insist on talking about what might happen at 11:30 PM when it's only 11PM and the show is over and the calculations are complete? Maybe they don't know what power and time are?
     
  12. origin Heading towards oblivion Valued Senior Member

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    11,888
    Not sure why this is so tough for you to understand.:shrug:

    Lets put it in terms of a car which is something you seem to understand a bit. When that gallon of gas is consumed most of it will go into the KE of the car and will ultimately be converted to waste heat. The altenator in the car can convert some of the energy into electrical energy; so the energy of the gas went into the internal combustion engine and some of that energy when into the alternator which was converted to electrical energy to run your 8-track stereo and your tape of Devo. Ultimately again all of that energy is converted to waste heat that cannot be recovered to do work.
     
  13. Motor Daddy Valued Senior Member

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    5,425
    And once again you continue to fail to understand what energy is. Amazing!!
     
  14. origin Heading towards oblivion Valued Senior Member

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    11,888
    But I could use the heat from the light to boil a small amount of water and use the steam to run a small generator that charges a battery, so the show is not over. I have now stored a fraction of the 1000 watt-hours!
     
  15. Motor Daddy Valued Senior Member

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    Good for you, but we aren't talking about what you might do in your crystal ball in the future, we are talking about how much work was done to light the bulb for 10 hours. Duh?
     
  16. origin Heading towards oblivion Valued Senior Member

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    11,888
    It is always interesting to discuss this stuff with you because you usually only have a rudimentary understanding of one narrow aspect of a concept and then anything thing that deviates in the slightest from your incredibly narrow understanding of that concept simply blows your mind.
     
  17. origin Heading towards oblivion Valued Senior Member

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    11,888
    Duh indeed.
     
  18. Motor Daddy Valued Senior Member

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    No, it's actually that I understand it so much, that I can spoon feed it to you in baby portions, and you take that as a sign of weakness. LOL

    Keep it up, I'm lovin' it!
     
  19. billvon Valued Senior Member

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    21,634
    The energy USED as 1000 watt-hours. That energy is no longer AVAILABLE.
    Or maybe you asked that question, and once again have forgotten what your own posts say.
     
  20. Motor Daddy Valued Senior Member

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    Who cares, we aren't talking about available potential, we are talking about measured energy (power times time). Duh??
     
  21. billvon Valued Senior Member

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    MotorDaddy:
    "Are you saying that the 1 kw-hr of energy consumed from the 10 hours of operating the 100 Watt light bulb is less available to do work after the 10 hours is complete?"
    Your trolling is getting weaker.
     
  22. Motor Daddy Valued Senior Member

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    No, I'm saying that operating the 100 Watt light bulb for 10 hours is 1 kw-hr of energy, PERIOD!


    I don't own a crystal ball like you do. Sorry, no fortune telling here.
     
  23. billvon Valued Senior Member

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    21,634
    So you don't know what happens after that. No big deal; some people don't understand basic thermo.
     

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