Can a magnet have more push force than it weighs?

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Discussion Overview

The discussion revolves around whether a magnet can exert a push force greater than its own weight. Participants explore this concept through examples, diagrams, and references to physical laws, focusing on the theoretical and practical implications of magnetic forces.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants assert that a magnet can indeed have a push force greater than its weight, citing examples.
  • One participant mentions the difficulty of levitating a magnet without additional support, suggesting that without rails or superconductors, the magnet will not remain in place.
  • Another participant questions the clarity of a diagram related to the forces between magnets, pointing out potential confusion regarding the direction of force arrows.
  • A later reply clarifies that the arrows in the diagram represent the push force, indicating an update to improve understanding.
  • One participant emphasizes Newton's third law, suggesting that the forces between the magnets are equal in magnitude.
  • Another participant notes the distinction between mass and force, explaining that forces should be expressed in Newtons rather than kilograms, and provides a calculation to illustrate this point.
  • There is a discussion about the equivalence of push and pull forces, with one participant questioning the focus on push force alone.

Areas of Agreement / Disagreement

Participants express differing views on the conditions under which a magnet can exert a push force greater than its weight. Some agree with the possibility, while others raise questions about the practical implications and the clarity of the underlying concepts.

Contextual Notes

There are unresolved issues regarding the interpretation of diagrams and the distinction between mass and force units. The discussion also highlights assumptions about the conditions necessary for achieving greater push forces.

JustSomeone
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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.
 
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Hello Som1, :welcome:

Simple answer: yes !
 
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JustSomeone said:
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.
https://s-media-cache-ak0.pinimg.com/564x/e2/3a/70/e23a7074e0e19066c1ae700be2593b74.jpg
e23a7074e0e19066c1ae700be2593b74.jpg
 
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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.
 
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Noob Question 2.png

https://www.physicsforums.com/attachments/146121
 
Last edited:
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?
 
Sorry about that, the glow is meant to represent the push force. I updated the arrow direction.
 
What does Newton's third law say?
 
Khashishi said:
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?

why are you limiting it to push force ... the pull is just the same
 
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JustSomeone said:
View attachment 146200
https://www.physicsforums.com/attachments/146121

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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