Why does it fail?

Discussion in 'Science' started by HereWeGoAgain, Dec 4, 2019.

  1. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    One of my favorites! So they don't fall in the hole.

    A friend of mine from Pakistan heard that and exclaimed, "Thats true! Back home they are triangular and fall in hole sometimes". :D
     
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  2. WillReadmore

    WillReadmore Well-Known Member

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    Earth rotation is slowing by about 1.7 milliseconds per century. Probably the largest reason is the pull of the moon's gravity on tides.

    The moon is gradually moving away from Earth. My understanding is that this will go on for a long time - continuing long after the sun has increased in size and evaporated and blown off Earth's oceans.

    I fully admit that is forever in human terms!
     
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  3. Aleksander Ulyanov

    Aleksander Ulyanov Well-Known Member

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    Most people know it, but it's interesting to talk about sometimes

    Nor does ignorance
     
  4. Aleksander Ulyanov

    Aleksander Ulyanov Well-Known Member

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    Look up "The Heat Death of the Universe"

    And then realize that something like 300,000 times as much energy exists at the ground state as does at higher than the Ground State. The Actual Heat Death of the Universe took place long, long ago,. We are part of the final expiring throes of everything. A tiny blip before endless death.
     
  5. ARDY

    ARDY Well-Known Member Donor

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    Prove it
     
  6. william kurps

    william kurps Well-Known Member

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    What does radiation have to do with perpetual motion and thermodynamics that this thread is about?
     
    Last edited: Dec 6, 2019
  7. william kurps

    william kurps Well-Known Member

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    Me thinks someone learned this in skool and rushed to make a topic about it thinking no one else knew about thermodynamics.

    Pure embarrassing
     
    Last edited: Dec 6, 2019
  8. william kurps

    william kurps Well-Known Member

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    Still thermodynamics..


    Like I said before any non college educated redneck grease monkey nascar fan knows this.


     
    Last edited: Dec 6, 2019
  9. william kurps

    william kurps Well-Known Member

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    Ok there are four ..and I will explain it by copying and paste..




    There are 4 laws to thermodynamics, and they are some of the most important laws in all of physics. The laws are as follows

    • Zeroth law of thermodynamics – If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.
    • First law of thermodynamics – Energy can neither be created nor destroyed. It can only change forms. In any process, the total energy of the universe remains the same. For a thermodynamic cycle the net heat supplied to the system equals the net work done by the system.
    • Second law of thermodynamics – The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.
    • Third law of thermodynamics – As temperature approaches absolute zero, the entropy of a system approaches a constant minimum
     
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  10. william kurps

    william kurps Well-Known Member

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    Worm holes bending space and time.
     
  11. Aleksander Ulyanov

    Aleksander Ulyanov Well-Known Member

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    OIC, OK, I've always understood that 0 and 4 are either special cases or derivations of 1 and 2 but I understand lots of things that aren't so.
     
  12. Aleksander Ulyanov

    Aleksander Ulyanov Well-Known Member

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    I can't, I remember I saw it in George Gamow's book 1, 2, 3, Infinity, You can look there yourself and see if you understand it. I take multiple Nobel nominees on faith.
     
    Last edited: Dec 6, 2019
  13. Aleksander Ulyanov

    Aleksander Ulyanov Well-Known Member

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    "Oh we'ull nevair go Warp 9 Cap'n, it'll shake me poor bairns apart"
     
  14. william kurps

    william kurps Well-Known Member

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  15. Aleksander Ulyanov

    Aleksander Ulyanov Well-Known Member

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  16. Derideo_Te

    Derideo_Te Well-Known Member

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    The inefficiencies of friction are the primary cause.
     
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  17. edthecynic

    edthecynic Well-Known Member

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    There is no 4th Law of Thermodynamics, but there ARE 4 Laws of Thermodynamics.
     
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  18. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    Someone with no training in science would see it that way. Newton's laws work in their domain of applicability, as do all theories in physics. Explain what I mean.
     
    Last edited: Dec 6, 2019
  19. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    That is a nonsensical answer. Why is it that everyone but you has provided some decent answers?
     
    Last edited: Dec 6, 2019
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  20. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    Since frictional forces are strictly a function of force and the coefficient of friction, the area drops out of the equation and in terms of friction, the width of the tire doesn't matter. But as you indicated, if you want to add rubber for a longer service life, you can go wider.

    The rotational inertia goes as the square of the radius, whereas it goes as the width, and not the square of the width. So it takes more energy get get a taller tires spinning, than it does a wider tire. So if you double the height of the tire, it takes 4 times as much energy to get it moving. If you double the width, it only takes twice the energy.

    There are other dynamics, such as the height of the wall and its ability to withstand the forces and not rip the tire apart. I remember reading that there are actually Ph,D papers written that cover other factors.
     
    Last edited: Dec 6, 2019
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  21. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    As a car drives down the road, one part of each tire on the car isn't moving. What part?
     
  22. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    Nope,
    solenoids = losses,
    inverter = losses,
    batteries = losses
    Current flowing in wires = losses,
    Motor = losses
    Generator = losses

    But it would make a nice heater. ;)

    Total instantaneous power is volts x amps x cos(a), where a is the phase angle

    The total power is independent of the voltage used. Voltage goes up, current goes down. Power remains the same, minus losses
     
    Last edited: Dec 6, 2019
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  23. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    And a lousy attitude and surfing the net doesn't equal an education. Nor does intelligence equal an education. That is why the smartest people in the world almost always have advanced degrees. You need both, high intelligence and an education, to accomplish anything in science.

    What many people do here is called crackpottery.
     
    Last edited: Dec 6, 2019
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  24. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    Great point! You are hitting on the same aspect of the problem in a different way. The total weight acting on the tire goes as pounds per square inch of contact area. So as much as you increase the total contact area, you also reduce the pounds per square inch. Strictly speaking, that is why the frictional forces are independent of the area, and depends only on the total weight on the tire, in this case, and the coefficient of friction. But you are right that it gets more complicated for any real application.
     
    Last edited: Dec 6, 2019
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  25. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    Forces due to friction are independent of contact area. But it is a great point that making a wider tire doesn't ensure that much greater contact area.
     

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