What is a Magnet?  Any material that can attract iron or any material that contains iron.

Properties of Magnets  Magnetic effects are strongest at the ends (poles) of the magnet  Two different poles  North and South  Magnetic Forces  Very similar to electric charges  opposite poles attract, like poles repel

The north pole of the guideway’s magnet should face it. The train uses less energy because there is very little friction. The train and the track get less wear. The train has a smoother ride.

Magnetic Fields  The magnetic field is the region around the magnet in which magnetic fields can interact.

Why Materials are Magnetic  Electrons move inside the atom which produce magnetic fields creating north and south poles within the atom  In magnetic materials, the atoms group together in regions called domains

Domains Domains are like little magnets with a north and south pole All of the atom’s magnetic fields line up with the fields of the domain

Magnetic Domains If the domains are aligned, the material is magnetic Atoms that are aligned create a strong magnetic field If the domains are not aligned, then the material is not magnetic

Figure 2 – pg 202

Figure 2- pg 203 You can feel the magnets repel or attract each other. The magnetic field is too weak at that distance.

Earth is a Magnet Earth’s magnetic South pole is lined up with Earth’s geographical North pole.

How is the Earth magnetic?  Earth’s magnetic field is produced by movement of electric charges  The core of the Earth is made of iron and nickel.  It is a solid because of major pressure  The outer core is a liquid  As the earth rotates, the liquid causes the electric charges to move, generating a magnetic field

Do the Math – pg 205 The pole has moved 857 km ( =857 km 857 km / 53 years = 16.2 km/yr

Bar magnet Cylindrical magnets Horseshoe magnets Cow magnets Disk/Ceramic magnets