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The rumor was you could make a magnet by leaving a piece of iron on a train track. The train going over it would magnetize it.

Is it true?

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up vote 3 down vote accepted

This is almost a duplicate to can you magnetize iron with a hammer . Have a look at it.

The only difference is that the rail lines are fixed in their north south direction for years. The iron in the lines themselves become magnetized and so the argument with the hammer should also hold , i.e. the small magnetic domains, momentarily freed by the impact, reorient to the magnetic field direction of North South of the earth's magnetic field. If the coin partially melts under the weight of the train, even better. It should of course be made from a ferromagnetic metal.

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during some mispent youth we used to place coins on a rail track. the end result was a smeared out coin about 3cm in length... – Nic Jan 11 '12 at 10:46
@Nic did you check them for magnetisation? – anna v Jan 11 '12 at 11:08
unfortunately we weren't that advanced! We just had fun squashing things... – Nic Jan 11 '12 at 11:28
@annav i actually did this a couple of times and also checked for magnetization, no it would't work – Jack Jan 11 '12 at 12:00
@Jack stainless steel is another story : – anna v Jan 11 '12 at 12:16

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