# Why isn't there any friction in magnet trains?

• DiMer
In summary, the conversation discusses the friction levels of a magnet train in a vacuum and how gravity may affect its movement. It is mentioned that while there may be some minimal friction from inhomogeneous magnetic fields, the train would still have low friction due to the homogeneous potential of gravity. The conversation also mentions the possibility of air resistance in a non-absolute vacuum on Earth. However, it is stated that a high-quality vacuum can greatly reduce friction and allow the train to travel without constant acceleration.

#### DiMer

Hi there, first poster here.

Something has been boggling me and I cannot seem to find the answer anywhere. I really hope that you will help me =)

A magnet train in vacuum has no friction whatsoever, right?

Then what about electron interactions between the 'rail' and the train itself due to the gravitational force?
I understand that if it was in space the train with would be in a perpetual motion and it would never stop. But if it's affected by gravity, why would it not move infinately? Is there some electron interactions between the rail and the train, or is it completely frictionsless?

Maybe I'm asking the wrong question, but if you would help me I'd really appreciate it!

Thank you

DiMer said:
A magnet train in vacuum has no friction whatsoever, right?
It still has some friction from inhomogeneous magnetic fields as they can act like an eddy current brake.

Gravity gives a very homogeneous potential, and no friction involved.

Considering we cannot make an absolute vacuum on Earth, there would still be some air resistance as well.

Wouldn't be very good as a passenger service though

Well...

A vacuum tube for a train would not get the best vacuum we can make, that would be way too expensive. But we can make a vacuum so good that friction with the remaining gas atoms becomes completely negligible.

## 1. What is friction in Maglev trains?

Friction in Maglev trains refers to the resistance that occurs when two surfaces come into contact and slide against each other. In the context of Maglev trains, it is the force that opposes the motion of the train as it moves along the track.

## 2. Why is friction an important consideration in Maglev trains?

Friction plays a critical role in the operation of Maglev trains as it affects the speed, efficiency, and safety of the train. Too much friction can slow down the train and increase energy consumption, while too little friction can cause the train to lose traction and derail.

## 3. How is friction reduced in Maglev trains?

Friction is minimized in Maglev trains by using electromagnetic forces to levitate the train above the track, eliminating the need for physical contact between the train and the track. Additionally, the use of specialized materials and designs for the track and train can further reduce friction.

## 4. Can friction be completely eliminated in Maglev trains?

No, friction cannot be completely eliminated in Maglev trains. While the trains are designed to minimize friction, some amount of friction is still present due to imperfections in materials and the environment. However, the amount of friction is significantly lower compared to traditional trains that rely on wheels and tracks.

## 5. How does friction affect the maintenance of Maglev trains?

The minimal friction in Maglev trains results in less wear and tear on the train and track, reducing the need for frequent maintenance. This can save time and costs for operators and also increase the lifespan of the train and track components.