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B Can a magnet have more push force than it weighs?

  1. Apr 11, 2017 #1
    Simple question. Can a magnet have more push force than the magnet itself weighs.
    Example: A magnet weighing 2kg having a push force equal to 3kg.
  2. jcsd
  3. Apr 11, 2017 #2


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    Hello Som1, :welcome:

    Simple answer: yes !
  4. Apr 11, 2017 #3


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  5. Apr 11, 2017 #4
    If you try to levitate a magnet on top of another magnet without some sort of rails, active feedback, or superconductors, then the top magnet will simply slide away or flip around and fall. If you do have rails, then it's easy to levitate a magnet on top of another.
  6. Apr 11, 2017 #5
    Last edited: Apr 11, 2017
  7. Apr 11, 2017 #6
    I don't understand the diagram. The magnets should be pushing on each other, but you have arrows pointing to the right. What is it pushing on?
  8. Apr 11, 2017 #7
    Sorry about that, the glow is meant to represent the push force. I updated the arrow direction.
  9. Apr 11, 2017 #8
    What does Newton's third law say?
  10. Apr 11, 2017 #9


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    why are you limiting it to push force .... the pull is just the same
  11. Apr 11, 2017 #10


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    The force from each magnet on the other will be equal in magnitude. Also note that a kilogram is not a unit of force, but a unit of mass (unlike the pound which is a unit of force). If your mass is in kg then your force should be in newtons (which itself is in units of kg*m/s2).
    If you take your magnets and place one on top of the other along with a rail to keep the top from sliding off of the bottom one, the magnitude of the force on each magnet will be equal to the mass of the top magnet times the gravitational acceleration. So in your example:

    2kg * 9.81 m/s2 = 19.62 kg*m/s2, or 19.62 newtons.

    This will be exactly enough to balance out the force of gravity on the top magnet and it will remain stationary. If you then add a small amount of mass or press down lightly on the top magnet the two will move closer to each other and until the forces once again balance out. At this point the force on each magnet is more than the top magnet's weight.
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