Question

Jolie builds a model of a maglev train. She uses disc magnets to levitate the train. A disc magnet has its north and south poles on its faces, as shown.

A round, 3 dimensional object labeled N on top and S on bottom.
What is the best way to arrange the magnets on the train and on the track so that the model train levitates?

flat, so that the north pole of each magnet on the train points up and the north pole of each magnet on the track points up
flat, so that the north pole of the magnets on the train point up and the north poles of the magnets on the track point down
on edge, so that the north poles of the magnets on the train point to the front and the north poles of the magnets on the track point toward the rear
on edge, so that the north pole of each magnet on the train and on the track point toward the rear of the train

Answer 1

To achieve levitation using disc magnets, the arrangement must allow for like poles to repel each other. In this case, the best way to arrange the magnets on the train and on the track is:

**Flat, so that the north pole of the magnets on the train points up and the north poles of the magnets on the track point down.**

This configuration will create a repulsive force between the north pole of the train's magnets and the south pole of the track's magnets (if the track's magnets had south poles facing upwards). Alternatively, to have them both be north poles, your original context specifies both are to be arranged with their north poles upwards or downwards.

In summary, if you want the train to levitate, align the north poles of the train bumps to repel the north poles of the track. This arrangement will allow the train to levitate due to the repulsive forces between the like poles.