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Vacuum Sphere

  1. Jun 19, 2008 #1


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    Hi to you all,

    May I just say I am not a physicist or the like so my questions may seem a bit green to you all, I wish to make something and need a little bit of info please.

    With regards to a vacuum sphere, if I was to spin an item within it would it spin freely or would there be forces against it? Second silly question, does an item within the sphere become any lighter/heavier or no difference?

    I hope the questions are worthy of a reply

    Kind Regards

  2. jcsd
  3. Jun 19, 2008 #2
    The vacuum will reduce aerodynamic drag, but that's all (assuming the sphere remains on Earth). You still have to deal with friction from the bearings supporting your spinning object.
    A vacuum has no effect on gravity, so the relative weight of your object will not change.
  4. Jun 19, 2008 #3


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    Thanks Pantaz for your reply, I am hoping i may be able to use opposing magnets to reduce the weight of my spinning object


  5. Jun 19, 2008 #4
    Magnetic bearings will reduce (but not eliminate) friction. Weight will be unchanged.
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