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- Thread starter carmatic
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In summary, the conversation discusses the relationship between distance and attractive force between a magnet and a piece of iron. The only available source for this information is Wikipedia, which provides a complicated mathematical expression for the force between two magnetic dipoles. It is possible to calculate the energy stored in a magnetic field and determine how it changes when a ferromagnetic material is placed around it, but the math can be messy and complicated.

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Dr_Morbius said:

as i have said, it only contains information on the force between 2 magnets, not between a magnet and a piece of ferromagnetic material

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Any luck with this?

I'm looking for this answer as well.

I'm looking for this answer as well.

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The force between magnets as a mathematical expression is complicated.

What I have found is the force between magnetic diople moments.

The only source that I remember specifically is wikipedia:

http://en.wikipedia.org/wiki/Magnetic_moment#Forces_between_two_magnetic_dipoles

which gave the force acting on [itex]\vec{m}_{2}[/itex] as being

[itex]\frac{3\mu_{0}}{4\pi \left\|\vec{r} \right\| ^{5}} \left[ (\vec{m}_{1} \cdot \vec{r})\vec{m}_{2} + (\vec{m}_{2} \cdot \vec{r})\vec{m}_{1} + (\vec{m}_{1} \cdot \vec{m}_{2})\vec{r} - \frac {5 ( \vec{m}_{1} \cdot \vec{r} )( \vec{m}_{2} \cdot \vec{r} ) \vec{r} }{ \left\| r \right\| ^{2}} \right] [/itex]

with [itex]\vec{m}_{1}[/itex] and [itex]\vec{m}_{2}[/itex] being the two magnetic dipole moments, and [itex]\vec{r}[/itex] is the displacement vector from the location of m_{1} to m_{2}

What I have found is the force between magnetic diople moments.

The only source that I remember specifically is wikipedia:

http://en.wikipedia.org/wiki/Magnetic_moment#Forces_between_two_magnetic_dipoles

which gave the force acting on [itex]\vec{m}_{2}[/itex] as being

[itex]\frac{3\mu_{0}}{4\pi \left\|\vec{r} \right\| ^{5}} \left[ (\vec{m}_{1} \cdot \vec{r})\vec{m}_{2} + (\vec{m}_{2} \cdot \vec{r})\vec{m}_{1} + (\vec{m}_{1} \cdot \vec{m}_{2})\vec{r} - \frac {5 ( \vec{m}_{1} \cdot \vec{r} )( \vec{m}_{2} \cdot \vec{r} ) \vec{r} }{ \left\| r \right\| ^{2}} \right] [/itex]

with [itex]\vec{m}_{1}[/itex] and [itex]\vec{m}_{2}[/itex] being the two magnetic dipole moments, and [itex]\vec{r}[/itex] is the displacement vector from the location of m

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Anyways, unless you have a very simple system (such as a uniform magnetic field and a ferromagnetic plate), the math you will need to solve your problem can be quite messy.

The attraction between magnets and ferromagnetic materials is due to the alignment of magnetic domains within the material. These magnetic domains are microscopic regions where the atoms are aligned in the same direction, creating a net magnetic field. When a magnet is brought close to a ferromagnetic material, the magnetic fields of the two objects interact, causing the magnetic domains in the material to align with the magnetic field of the magnet. This alignment creates a strong attractive force between the two objects.

The strength of the attraction between a magnet and a ferromagnetic material is inversely proportional to the square of the distance between them. This means that as the distance increases, the strength of the attraction decreases at a rapid rate. For example, if the distance between a magnet and a ferromagnetic material is doubled, the strength of the attraction decreases by a factor of four.

Yes, the attraction between a magnet and a ferromagnetic material can be blocked by other materials that are not ferromagnetic. These materials, such as wood or plastic, do not have aligned magnetic domains and therefore do not interact with the magnetic field of the magnet. This means that the attraction between the magnet and the ferromagnetic material will not be able to pass through these non-magnetic materials.

The ability of a material to be attracted to a magnet depends on its composition and structure. Ferromagnetic materials, such as iron, nickel, and cobalt, have a specific arrangement of their atoms that allows them to have strong magnetic properties. Other materials, such as copper or aluminum, have a different atomic structure and therefore do not have strong magnetic properties.

Yes, the attraction between a magnet and a ferromagnetic material can be affected by temperature. As the temperature of the material increases, the motion of the atoms within the material also increases. This can cause the alignment of the magnetic domains to become disrupted, reducing the strength of the attraction between the magnet and the material. At very high temperatures, the material may lose its magnetic properties altogether.

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