Investigating Magnetic Train Forces: A Puzzling Inquiry

In summary: I don't know, that's a pretty radical hypothesis.maybe because the magnets are interacting with each other in a way that is analogous to classical forces?I don't know, that's a pretty radical hypothesis.thanks for the input!In summary, Ray's teacher used a Magnetic train to demonstrate electromagnetic phenomena to advanced learners. He told them to investigate the forces and how certain parameters affect the velocity. However, Ray does not understand how there can be a velocity with a force. He asks the expert for a thought-provoking impulse. The expert responds that a force can change velocity, and that certain forces appear. They also discuss how a magnetic train works.
  • #1
mathewmical
22
0
Hello
I hope you know the phenomenon called "Magnetic train". My teacher used it in classes to demontrate electromagnetic phenomena. So he told the advanced learners (however, here I am xD) to investigate it, especially the forces and how certain parameters affect the velocity. But I do not understand at all how there can be a velocity with a force? and which forces appear? I hope you can give me at least a thought-provoking impulse.

thanks a lot

Ray

upload_2015-12-20_20-21-53-jpeg.93542.jpg

Image added by mfb to clarify which type of train is meant (see page 2)
 
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  • #2
mathewmical said:
But I do not understand at all how there can be a velocity with a force?
How do you mean that question?
A force can change velocity.
mathewmical said:
and which forces appear?
Descriptions of the train concepts discuss that.
 
  • #3
yes but there seems to be a constant velocity and i wonder how this can be. woundn´t it be changing all the time?
 
  • #4
Due to inertia, something with no net force will maintain a constant velocity. A magnent suspending a train can precisely counteract the force of gravity, allowing the train to move at a constant velocity because the sum of forces is zero (they act in opposite directions). I think you might be asking something deeper than that, though, I'm not sure.
 
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  • #5
very interesting, thank you! i agree but how does a magnet counteract the force of gravity when they are perpendicular to each other?

i think there is only the force of attraction and the force of repelling. and the force caused by friction that opposes these two other forces. And gravity.
 
  • #6
It may be called a "magnetic train" but the magnets are not used to attach each carriage to the next one; the main function of the magnetic field is to raise the train off the tracks...to give a small clearance. [emoji52]
 
  • #7
that´s not what i meant, my experiment refers to a battery in a solenoid where there are magnets attached on each side of the battery. if you put it into, it´ll start to move.
 
  • #8
I think the OP is referring to this particular experimental demonstration, where the "train" is a battery with magnets attached to its ends, traveling through a wound copper wire "track".
 
  • #9
yes that´s right
 
  • #10
mathewmical said:
yes but there seems to be a constant velocity and i wonder how this can be. woundn´t it be changing all the time?
My instinct would be that this is due to the back-emf that arises from electromagnetic induction effects...though I'm not that sure...imhomogenous magnetic fields are always tricky to analyse
 
  • #11
so it is possible that it gains speed due to the back-EMF and than move till the battery is empty because of the forces.?
 
  • #12
mathewmical said:
very interesting, thank you! i agree but how does a magnet counteract the force of gravity when they are perpendicular to each other?
It does not, and there is no need to. The train is supported from below by the coil.
i think there is only the force of attraction and the force of repelling. and the force caused by friction that opposes these two other forces. And gravity.
It is useful to analyze horizontal and vertical forces separately.
 
  • #13
hmm i just thought there are only horizontal forces because of the friction
 
  • #14
Well, there is certainly a vertical force from gravity, and something balancing it (so the train doesn't fall through the table). Otherwise the train would float, and there would be no (horizontal) friction either.
 
  • #15
of course, but theforce from gravity is only important for the friction and the normal force neutralize it. right?
 
  • #17
How a maglev train works..

https://www.quora.com/How-magnetic-levitation-train-works
 
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  • #18
CWatters said:
How a maglev train works..

https://www.quora.com/How-magnetic-levitation-train-works
This is not the type of train discussed here.
 
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  • #19
mathewmical, I think you should edit your first post to include a picture of that particular experimental demonstration you're referring to, because "magnetic train" immediately causes most people to think about maglev trains =p
 
  • #20
okay i´ll do so :D
 
  • #23
thanks a lot
 
  • #24
okay i just got another idea: if i only focus on, like, 3, single loops. if the battery touchs two of them, the current flows and the like pols repel each other with FR, so on the battery there will be twice the force because of Newtons third law. the same with the unlike poles . so all in all there's four times FR so there's an acceleration. then, due to inertia it moves on to the next loop and then it starts again? then its resonable to have an apparently constant velocity. what do you think about it?
 
  • #25
If FR refers to friction: why do you expect fixed relations between magnetic forces and friction?
 
  • #26
FR refers to the force one magnet exerts on the other one (R due to 'repelling'). maybe if i manage to calculate the force I can figure out the acceleration between two loops.
 
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  • #27
or wait could it be that first there's an acceleration, but due to the voltage induced by the fixed magnets the voltage of the battery will be compensated so it will remain with a constant velocity?
 
  • #29
That´s all? then is there a way to calculate the velocity?
 
  • #30
Not with reasonable effort.
You can make rough estimates if you know friction and some coil properties, but it's not like a typical homework problem where you plug in 3 numbers in a formula and you are done.
 
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  • #31
But it´s possible right? if i can calculate the magnetic field of the coil, i´d be able to ?
 
  • #32
It is not impossible. It is a physical system, it is possible to simulate it. It is just a lot of effort to get it right.
 
  • #33
Okay then, but thank you very much for all your quick replies!
 

Related to Investigating Magnetic Train Forces: A Puzzling Inquiry

1. What is a magnetic train?

A magnetic train, also known as a maglev train, is a type of train that uses magnetic levitation to move along a track without any physical contact between the train and the track. This technology allows for faster and smoother travel compared to traditional trains.

2. How does magnetic levitation work?

Magnetic levitation works by using the repulsive force between two magnets with like poles facing each other. In a maglev train, the train has magnets on the bottom and the track has electromagnets that are switched on and off rapidly. The repulsive force between the magnets causes the train to levitate and move forward.

3. What are the benefits of using magnetic trains?

There are several benefits to using magnetic trains, including faster speeds, smoother rides, and lower maintenance costs. Maglev trains can reach speeds of over 300 mph, reducing travel time significantly. The lack of physical contact between the train and the track also results in a smoother ride and less wear and tear on the train. Additionally, the absence of wheels and tracks means there is less maintenance required.

4. What are the challenges of implementing magnetic trains?

One of the main challenges of implementing magnetic trains is the high cost of construction. Building a maglev train system requires specialized infrastructure and technology, making it a costly investment. Additionally, the technology is still relatively new and there may be safety concerns that need to be addressed. There may also be challenges in integrating maglev trains with existing transportation systems.

5. How can we investigate the forces involved in magnetic trains?

There are several ways to investigate the forces involved in magnetic trains. One approach is to use mathematical models and simulations to analyze the forces and predict the behavior of the train. Another approach is to conduct experiments using scaled-down models or prototypes to measure the forces and observe their effects. Additionally, studying the existing maglev train systems and their performance can provide valuable insights into the forces at play.

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