Magnets, attract vs. repel

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I wonder if that is really true. One might be able to hold them in a position that by all rights appears to be touching but is it really or is the magnetic force enough that it is not possible?

I don't know the answer, just thinking out loud.

Bob
 
I agree with Jeff. It comes from one of Newton's laws of motion: things will move in the direction of the greatest force (actually, in the direction of the net summation of all imposed forces). If you have two opposing forces (magnetic repulsion and a push from a human hand), and if the push is the stronger of the two, then the magnets will move towards each other. All you have to do to prove it can be done is to listen for the sound of "metal against metal" contact.
 
It is my belief that all forces in nature are actually repulsive. The two magnets when placed near each other oriented with unlike poles are not being pulled together or under an attractive force, but are actually being pushed together... Anyone want to try to prove me wrong???
 
bphgravity said:
Anyone want to try to prove me wrong???
Click to expand...
That is easy. But it would require you to accept the notion that a "pull" is defined as a force tending to move an object in the direction of the entity that is creating the force, and that "push" is defined as a force tending to move an object in the direction opposite to the entity that is creating the force.

One of the earliest lesson in Physics class is drawing force diagrams. You show an object, and you draw arrows to depict the forces being imposed upon them. For example, if you consider a ball that you hold in your hand, there will be two arrows. One will point downwards, representing the force of gravity. The other will be upwards, representing the force imposed on the ball by your hand. If you hold your hand steady, then the two forces will be equal, and the ball will not move. This will be represented in the diagram by two equal (but opposite) arrows.

But if you were to let go of the ball, then there would be only once force, and you would represent it with only one (downwards) arrow. The force diagram will depict one external force, and will make clear that the object will move in the direction of that force.

Now draw a similar force diagram showing two magnets, lying on a table, with opposite poles facing each other. The drawing will show two objects, and two arrows. The two arrows will be in opposite directions. That is, the force imposed on the left-hand magnet will be towards the right, and the force imposed on the right-hand magnet will be towards the left. There are no other relevant forces, no other arrows.

Actually, you could also draw the same two arrows I mentioned above, relating to the hand holding the ball (i.e., gravity force downwards, force from table upwards). But since those two cancel each other out, I am calling them not relevant to this problem. I am also disregarding friction, but adding friction to the story does not alter its conclusion.

There is only one force on the left hand magnet, and it is to the right, and the magnet will therefore move to the right. Since the thing that is imposing the force on the left-hand magnet is located in the direction of motion of the left-hand magnet, that force is, by definition, a "pull." In addition, since there is no force originating to the left of the left hand magnet to compel it to move to the right, then one must conclude that there is no "push." I could say similar things about the force imposed on the right-hand magnet by the left-hand magnet.

Q.E.D.
 
bphgravity said:
Gravity isn't an attractive force either... :wink:
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I suppose that depends of the relative attractiveness of whatever (or whoever) gravity would otherwise attempt to attract. :wink:
 
Charlie, Bryan,

Thank you for the great replies.

Charlie, using your same example, except the poles are alike and you are holding them to the table next to each other, would that be a 'push'?
 
Magnets are fun.

magnoids.jpg


But so are green lasers:

49449797.Composite2_Small.jpg

Yes, that laser lit a match on fire.
http://wickedlasers.com/products.php?content=advanced
Make note of the power rating.

Could it be a new method for cutting electrical tape without ripping it?
http://wickedlasers.com/videos/01.wmv

Hah, geek toys :p
 
bphgravity said:
It is my belief that all forces in nature are actually repulsive. The two magnets when placed near each other oriented with unlike poles are not being pulled together or under an attractive force, but are actually being pushed together... Anyone want to try to prove me wrong???
Click to expand...


no, but there are a whole bunch of quantum physicists trying to prove you right at this very moment. this isnt exactly my field of expertise but from what i have seen and read physicists are trying to figure out why the speed that sent matter shooting through the universe from the big bang hasnt slowed any in billions of years and in fact the gaps in between large matter clusters like planets and suns is actually being sped up. they have been measuing the signals from pulsars and the red shift from supermassive blackholes and found that items are attracted to each other but once they reach a certain threshold there is something that begins to repel them from one another exponentially. supposedly this force is always at work repelling matter but magnetic fields and/or gravity is a stronger force so a certain distance must be put inbetween the two objects before the "force" becomes more powerfull then gravity and begin to repel. they called it "dark matter". and it wasnt antimatter because we allready have like a microgram of it sitting in some particle accelerator somewhere in france.

neat stuff, might wanna look into it. even if you were trying to be sarcastic with your post (i dont know) your theory may have validity.
 
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