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Reaction missing

  1. May 3, 2005 #1
    "Try this. Get a bicycle tire and put a couple of handles on the hubs. Spin the tire as fast as you can and sit down on a revolving chair (except make sure the chair is still). Turn the spinning tire over.

    What happens? You'll find you can get some pretty good fine control on just how fast you spin and how fast you stop by the angle you hold the tire at"

    wheres the reaction to this spin?

    if i spin by using my feet on the ground there an oposite and equal reaction in the earth spinning the oposite way than the chair

    i cant see any reaction in this case at least not oposite in spin to that of the chair

    now imagine this

    you have the wheel with a certain angle, not vertical

    and the wheel winds and rewinds because it has a string in the inside

    the wheel spins 100 revolutions in one sense and another 100 in the oposite sense

    so while the wheel spins in one sense the chair rotates to one sense and when the wheel turns oposite sense the chair rotates oposite sense

    now try this:

    when the wheel has almost completly winded up make the angle be the symetrical so now the rotation of the chair is in the same sense than initially
    and when the wind up is about to rebound the oposite sense again correct the angle once more so precesion always has the same sense

    wouldnt the wheel acelerate constantly the rotation of the chair by using the work of moving the angle of the wheel?

    what would happen if you dont aply work to change the angle of the wheel but you gear it with the spin of the wheel ?

    it doesnt make any sense to say that the wheel would acelerate the chair that would acelerate the wheel
  2. jcsd
  3. May 3, 2005 #2
    Riddle me this batman: If you don't understand what is going on in the first part (a free body diagram would help you a lot) then how can you generate a thought experiment in second part? How can you conceive to progress from A to B without the foggiest understanding of A itself? Moreover, you need to know what preceeds A to understand A. How can you even imagine a thought experiment with no understanding of the thought itself?

    You're killing me here. My stomach actually turned when I read this if I may be so bold. Here, www.hyperphysics.com is a good source for very basic and general knowledge on a broad range of physics topics. Go to your local library and get a physics book. Take a physics class (try taking a physics class for scientists and engineers so you will actually have to derive all of the equations instead of a college level class where many eqn's are simply given).

    To answer your first question---There is no reaction to spin. Spin is not a force. There's a pseudo force referred to as centripital force; however spin itself is not a force and has no reaction.
  4. May 3, 2005 #3
    to say that with interior work you can make an object go from stillness to rotating aceleration seems ackward to me since space is homogeneus and isotropic so it has no hooks

    in what do you hold to aquire spinning aceleration if you dont acelerate anything the oposite way?
  5. May 3, 2005 #4

    Chi Meson

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    Your incorrect use of the word "acceleration," and your blithe, inconsequential assertion of "homogenious and isotropic space," in addition to all your other posts make it clear that you do not know what you are talking about.

    You ignorence of the VERY SIMPLE law of conservation of angular momentum, plus your belief that the very interesting phenomenon that you describe has been somehow covered up or ignored by the "establishment" because it is too hard to understand is insulting. Take a physics class.
  6. May 3, 2005 #5
    i though this forum was for people to learn

    well im asking a question i expect an answer

    in what does the mass hold to rotate if space has no hooks?
  7. May 3, 2005 #6
    besides its been accepted in this forum that translation can be transformed into rotation

    if translation is a force rotation must be a force since force doesnt disapear but transforms
  8. May 3, 2005 #7
  9. May 3, 2005 #8
    Who said translation was a force?
  10. May 3, 2005 #9
    to produce a translation from stillness you have to aply a force

    the same can be said for rotation

    if the force is to produce translation apears a reaction the oposite way that the force is aplied, said with another words an equivalent mass is pushed the oposite way

    my question is where is the reaction to the force that produces the rotation?
  11. May 3, 2005 #10
    Dude, draw a free body diagram. The action and reaction forces will be readily apparent.
  12. May 3, 2005 #11


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    unfortunately, while this board is a very good place to get answers to specific questions, it is not such a good place to learn physics from scratch. To do that you much take a course, or try reading a text book such as Fundamentals of Physics by Haliday and Resnick.

    You have way to many gaps in your physical knowledge to understand most of what you are told. So please make an effort to learn the basics. Feel free to post questions about those basics as you learn.
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