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Physical kick drive

  1. Aug 27, 2009 #1
    Hello friends.

    I simply couldn't find an easier way to explain what I'm looking for, so here's a drawing.

    And my questions are:
    1. Does something similar even exists, and how is it called?
    2. With the proper masses/ratios/calculations/whatever & control system, is this device able to provide propulsion, at least in vacuum or whatever?

    Thank you very much!

    Attached Files:

  2. jcsd
  3. Aug 27, 2009 #2


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    Gold Member

    Welcome to PF, Ketamynx.
    I must admit that, even with my reading glasses, I can't make out some of the text.
    I see two immediate problems. One is that if the permanent magnet is spherical, as shown, it will merely flip over and be attracted to the electromagnet.
    The other is that there doesn't seem to be a mechanism to translate the lateral movement of the permanent magnet to a rotational one. At the least, it should be in a curved channel rather than a straight one.
    As for the practicality of the device... I'll leave that for someone more knowledgeable to answer.

    edit: I just took a closer look at the thing and realized something that I overlooked the first time. Your electromagnet and the containment tube for the permanent magnet seem to be mounted on the same structure. At first, I thought that they were separate. You would get an equal and opposite thrust imparted to the electromagnet as compared to the permanent one. No net result.
    Last edited: Aug 27, 2009
  4. Aug 28, 2009 #3


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    Staff: Mentor

    In the second diagram, the magnet will move left and the ball will move right. Then in the third, the ball will move left and the magnet will move right, bringing them back to where they started.

    No, what is shown in the diagrma is not possible. It is an obvious violation of several physical laws including conservation of energy and Newton's laws of motion.
  5. Sep 2, 2009 #4
    To every action there is always an equal and opposite reaction..... This is why people don't actually fly off there feet when shot - the person doing the shooting would have to do the same.
  6. Sep 4, 2009 #5
    Thanks, I can't believe I forgot the laws of movement.

    But additionally, I have a few other wonders:
    1. We fly a rocket, and at it's end we mount a huge rubber bag or whatever to get back all the burnt gas and carry it back, would this work practically or will it follow the same laws? And 2., say you're in total vacuum empty space. Can you turn around, or gain speed, or move anything without the aid of any external object, all by yourself?

    Thanks and please be good to me, I'm here only to make my silly questions clear.
  7. Feb 27, 2010 #6
    Hello, I'm back with an animation.

    Please tell me if this can work and if it's worth making improvements.


    Attached Files:

  8. Feb 27, 2010 #7

    Doug Huffman

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    Gold Member

  9. Feb 27, 2010 #8


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    Staff: Mentor

    The law of conservation of energy has not been revoked since you last posted. You are wasting our time and yours. Thread locked.
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