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Force multiplication with magnets

ccurtis

Active Member
Hello,

Say I restrict the movement of a magnet to a vertical axis using a vertical plastic tube within which the magnet is placed, and then likewise do the same for another magnet to the horizontal axis using a horizontal tube, and then place the bottom end of the vertical tube above and against one end of the horizontal tube. The magnets are oriented such that when the magnet in the horizontal tube is pushed to a point directly underneath the magnet in the vertical tube, the vertical magnet will be repelled (opposing magnetic poles) and lifted to some maximum height within the vertical tube.

Questions: Will the energy required to push the magnet in the horizontal tube a short distance so as to be located directly underneath the magnet in the vertical tube (essentially to overcome fictional force) be less than the change in potential energy of the magnet in the vertical column, due its increased height from the magnetic repelling force? And, if yes, would not that answer be a violation of the law of conservation of energy?
 

ccurtis

Active Member
I have no doubt about that, but rather wonder if it would be a violation of that law. The frictional force is only some fraction of the normal force and the magnetic force between the magnets exists independent of the input force.
 

Pommie

Well-Known Member
Most Helpful Member
The force required will be the force to lift both magnets as that is what you are doing.

Mike.
 

alec_t

Well-Known Member
Most Helpful Member
the magnetic force between the magnets exists independent of the input force.
No. As you move the horizontal magnet towards the vertical one the repulsion force will increase and there will be an increasing force opposing the horizontal movement.
 

ccurtis

Active Member
No. As you move the horizontal magnet towards the vertical one the repulsion force will increase and there will be an increasing force opposing the horizontal movement.
Understood. I can't help but wonder though if the horizontal component of repulsion force is significantly less than the vertical component. But, indeed, I now see there is more than just fictional force to overcome.
 

Rich D.

Active Member
The total input energy would be the frictional force which would be lost as heat, and the force that raised the vertical magnet. From your imaginary experiment there is no other energy added to this system.

In any event where the vertical magnet drops back to its original position, whatever energy from the rise will be returned. Where could that energy possibly come from? It has to be the force that pushed it up there in the first place, which would have to be most of the the energy applied to the horizontal magnet less the heat. The law say there can't be any more energy created, so it all came from your input. There is no other energy added, so no more can possibly be returned...that is if you believe in classical physics.
 

BR-549

New Member
Imagine a plastic tee tube. Invert it. Drop magnet down vertical leg. NP first. Now blow horizontal magnet across one side of tee. NP first. As the horizontal magnet approaches the vertical magnet......the magnetic poles interact. The magnetic flux will transfer the momentum from the horizontal magnet to potential in the lift or height of the vertical magnet. It bucks up against gravity. The horizontal magnet will decelerate til it hits the mid points of the poles. At that time.......the pole interaction reverses......transferring the potential height of the vertical magnet back into acceleration of the horizontal magnet. The horizontal magnet accelerates down the other end.
 

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