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Can magnets act as accelerators to certain objects?

  1. May 15, 2012 #1
    Hallo everyone!


    I was wondering is it possibile to use magnetic attraction/repulsion to increase speed or rotational speed of an object?

    this video is a quick illustration of what I mean.

    If it possibile to use magnets as "accelerators" how is it possibile? from magnetic fields? or what?

    Giving a certain object a bit of energy then accelerate it by using magnetic force?

    Hyp,
     
  2. jcsd
  3. May 15, 2012 #2
  4. May 15, 2012 #3
    Hey Infinitum!

    I know it is but I wanted to make sure even for revolving object could that principle be applied? Also to want extent can I expect the acceleration to go on?

    My idea is to accelerate a wheel(increase it rpm) by using magnets.
    I'm planning to build a specific wheel design with magnets for my bike this is kinda interesting!
     
  5. May 15, 2012 #4
    Yes, you can apply that same principle to revolving objects too. But, as far as your idea is concerned, it would be really hard, since this principle relies on electromagnets quickly and continuously changing their magnetic nature i.e. If one magnet is pushing the ball/train forward, the next magnet would be pulling the train. In the immediate next second, this magnet would change to pushing the train/ball and so on. It requires a careful understanding how the magnet will effect the motion.

    To get a better idea : http://www.transrapid.de/cgi/en/basics.prg?session=75c445d44fb242d6_199228&a_no=43
     
  6. May 15, 2012 #5
    Thank you! So far I can build a disc with opposing + attracting faced magnets and experiment from there!

    Im trying to avoid electromagnetism as my final resort if normal magnets wouldn't do the job well!

    Thanks Infinitum!
     
  7. May 15, 2012 #6
    Wait...isn't magnetic attraction/repulsion exactly how all (if not most) electric motors work?
     
  8. May 15, 2012 #7

    russ_watters

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    Yes, but Hypo apparently thinks you can do it with permanent magnets. Incorrectly. Sorry Hypo, there is no perpetual motion. No free lunch.
     
  9. May 15, 2012 #8
    This, for emphasis.

    Also, the way you've written your post, makes me think that you will have the magnets on the bike? That doesn't work either. The magnets will experience an equal force backward, resulting in a net force of zero. You need to keep them external.
     
  10. May 15, 2012 #9
    I swear to god when I was typing this thread I knew someone will bring this up... IM NOT INTERESTED IN THAT ANYMORE ITS DEAD.

    I just want to study in magnets in general electromagnetism well lead me to my goal at the end but I wanted to see if permeant magnets could possibly do the job in mind. WHICH IS "ACCELERATE OBJECTS". No longer interested in perpetual motion machines because I've been convinced by my own eyes a million times so I'm done.

    Now I had many pieces of magnets laying around the house so I'm being productive using other ideas.
     
  11. May 15, 2012 #10

    russ_watters

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    So...you aren't interested in perpetual motion machines, but you are interested in using permanent magnets to propel a bike? How can you reconcile those two statements with each other?

    As Shakepeare once said, "a rose by any other name would still be perpetual motion".
     
  12. May 15, 2012 #11

    russ_watters

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    Yes. But with electromagnets of course, not with permanent magnets.
     
  13. May 15, 2012 #12
    Ooook thanks... I'll stop the non sense of the "perpetual motion" right here... I have NO intention anymore of building theses devices I bought I lot of magnets that are useless right now I'd like to build something cool with them and a accelerator is one of um.

    Before doing it I wanted to make sure I could achieve it reason being I tried placing magnets in a certain position and the force candled the motion all together BECAUSE of the net force of zero... So I was wondering how the hell can I make an object go fast from the magnetic fields without using electricity mainly because I don't really know how to build an electromagnet...(The copper wiring part specifically I'm lost in)
     
  14. May 15, 2012 #13

    How is it possibile to accelerate an object using magnets when the NET FORCE =0?

    I've said before I used a system using a disc and proved this method where magnets are attached to a disc and a stationary magnet installed its pulls and pushes = 0 overall and I'm done with that because its useless.
    Now I'm wondering whats that effect how is it possibile to accelerate an object with permeant magnets when my disc proved otherwise? A few simple projects demonstrate that in the link posted up but is it possibile to speed a revolving object from its original speed using magnets? Now you would say it is possibile but with electromagnets ONLY.

    Now thats an answer im looking for because I'm confused about this matter and would like to understand it more.
    Perpetual motion devices are of the past and thats it!
    I don't want to propel an object... I'd like to accelerate a propelling object using magnets(preferably permanent magnets if its not possibile then I'll use electromagnets instead.)
     
    Last edited: May 15, 2012
  15. May 15, 2012 #14
    Indeed, both my initial posts specifically state that you need electromagnets to change fields continuously. As for building an electromagnet, its really simple. An iron nail/bar, copper wire and a battery. Wind the wire around the iron nail/bar tightly, preferably two or three layers of wire for strength, and connect it to the battery. Done! Now say if this produces a certain magnetic field in the iron bar, then inverting the battery ends will cause an opposite field.

    But if you notice, the magnetic fields are continuously changing, and this is possible only with electromagnets. Permanent magnets have fixed magnetic fields.

    Propelling means to accelerate. If you want to accelerate any object, try making a motor.



    Note, the motor works because the net torque on it acts like a couple. The net force is zero.
     
    Last edited by a moderator: Sep 25, 2014
  16. May 15, 2012 #15

    russ_watters

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    There can be a net force, it just can't be continuous. The magnets in the video clip have to be manually pulled apart after each run.

    [Edit: too late...]
     
    Last edited: May 15, 2012
  17. May 15, 2012 #16

    Thanks! I have neodymium magnets all use those in the system!
    Although my question is how much electricity does one magnet need to change its magnetic pole? my magnets are fairly small half the size of a coin + do I have to constantly keep it charged with electricity or its a on and off system?
     
    Last edited by a moderator: Sep 25, 2014
  18. May 15, 2012 #17

    Drakkith

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    A permanent magnet cannot change its pole. For an electromagnet you need to keep a constant current through it to keep the magnetic field. Reversing the direction the current flows reverses the poles of the electromagnet. No extra electricity is needed to reverse the current.
     
  19. May 15, 2012 #18
    Ok if I used a 1.5V @ 0.200amp battery would it make the magnet an electromagnet? is there a specific charge requirement to power an electromagnet?
     
  20. May 15, 2012 #19

    russ_watters

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    You don't make an electromagnet from a permanent magnet. You make an electromagnet from a coil of wire... often with a non-magnetized iron core.

    Also, there is no such thing as a ".2 amp battery". You probably mean .2 amp-hour.
     
  21. May 15, 2012 #20

    Drakkith

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    You need to read up on electromagnets and related articles. Without understanding even the basics you have very little chance of building anything more complicated than a battery with a wire. We cannot give you step by step instructions on how to build this.
     
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