Message-Id: <v01540b1bb13c9cf114f4@[192.174.2.173]>
Date: Mon, 23 Mar 1998 15:24:03 -0800
To: pinhole@exploratorium.edu
From: pauld@exploratorium.edu (Paul Doherty)
Subject: Re: magnet workshop
Don
You are on the right track.
The magnet magnetizes the iron filings so the iron filings become magnets
and so interact wit each other.
The result is that iron filings attract each other end to end (NS NS NS
...)and repel each other side to side NS
NS this is why the filings organize
themselves into line-like arcs from one pole to another, and also why the
lines are separated from each other.
Indeed a weak magnet can be made stronger by placing iron near it. This was
often done in the old days when all we had were weak magnets.
Iron filings placed between two lines of iron filings would be repelled by
the lines.
In general the magnetic field of the filings simply adds to the field of
the magnet that aligned them. If the creating maget is weak its strength
can be changed by the field from the filings.
Paul D
>Paul
>I just did a discussion of the iron filings activity with bar magnets. My
>understanding is that the bar magnet induces magnetic properties in the
>filings and they align themselves with the field (alternatively, they respond
>to the force of the bar magnet's field much as a compass would). Couple of
>questions arose from that discussion: the collection of magnetized iron
>filings must have a magnetic field, too. What effect do these fields have the
>bar magnet's field? Is it possible for the fields of the filings to be
>stronger than that of the bar magnet? If a new piece of iron filing were put
>in the space between two of the lines (and the friction with the surface is
>small enough to permit the filing to move) would it be attracted to an
>existing line?
>Don
>How fortunate you should begin this dialogue at this moment.