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Electromagnetic materials

  1. Jan 28, 2015 #1
    hello

    which is the lightest material that electromagnetism can set it in motion?

    thanks!
     
  2. jcsd
  3. Jan 28, 2015 #2

    mfb

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    The electromagnetic interaction can set everything in motion in some way. What do you mean with "lightest material"? Smallest mass, lowest density, something else?
     
  4. Jan 28, 2015 #3
    I am looking for a strong material but lightweight, that can be set in motion under electromagnetic field OR can be induced into a magnet if electrified
     
  5. Jan 28, 2015 #4

    mfb

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    That is still very vague. Even contact interactions ("pushing things") are influenced by electromagnetic interactions.

    What do you want to do?
     
  6. Jan 28, 2015 #5
    basically a kind of motor

    I have a rotating disc
    I want to link that disc to another disc and make them both rotating together
    but I want them not to be connected mechanically, but electromagnetically
    I want by electrifying them somehow, to make them rotate as one (either attached physically or not), but secured together electromagnetically
     
  7. Jan 28, 2015 #6

    mfb

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    Are the disks next to each other? Permanent magnets should be the easiest solution. Replace them by electromagnets on one disk if you want to be able to switch the connection.
    You won't get much power transfer without a mechanical connection or very large and heavy magnets.
     
  8. Jan 28, 2015 #7
    the electromagnetic interaction can only move things that have an electrical charge, right?
     
  9. Jan 28, 2015 #8
    All atoms have electric charges, both positive and negative ones. So basically everything interacts with electromagnetic fields, if the fields are strong enough. Even things that "normally" are not magnetic or electrically charged.



    To make an electric motor out of two discs, you would have to attach a series of magnets with opposing polarities on one disk, and a set of coils on the other, and then
    power the coils with the right AC frequency.

    http://en.wikipedia.org/wiki/Brushless_electric_motor
     
  10. Jan 28, 2015 #9
    large and heavy magnets or high currents and high voltages?
    I don't want them to be permanently magnetic, that's why I want them to be electromagnetic
     
  11. Jan 28, 2015 #10
    neutrons don't have electric charge
     
  12. Jan 28, 2015 #11

    mfb

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    Depends on the details of the setup, maybe all together.
    Probably impractical, but hard to tell without any estimate of the size and scope of the project.


    @Dinis Oliveira: Free neutrons are unstable, so in normal matter they are always bound in nuclei with protons, and then you have charged objects around again. In addition, neutrons contain quarks, and those are charged.
     
  13. Jan 28, 2015 #12
    what does unstable mean here?
     
  14. Jan 28, 2015 #13

    mfb

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    They decay (to proton+electron+neutrino).
     
  15. Jan 28, 2015 #14
    and that proton and electron won't form an atom?
     
  16. Jan 28, 2015 #15

    mfb

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    Extremely rarely, usually the particles shoot away with high energy that got released in the decay. Where is the relevance for the topic? Please open a separate thread if you have more questions about neutron decays.
     
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