Senior room pupils have been learning lots about forces & magnetism.
Playing with magnets is one of the first bits of science most children discover. That’s because magnets are easy to use, safe, and fun. They’re also quite surprising. Remember when you first discovered that two magnets could snap together and stick like glue? Remember the force when you held two magnets close and felt them either attract (pull toward one another) or repel (push away)? One of the most amazing things about magnets is the way they can attract other magnets (or other magnetic materials) “at a distance,” invisibly, through what is called a magnetic field.
You cannot see the magnetic force around a magnet, but you can see the effects of its presence when an iron nail sticks to a magnetic field of a bar magnet! The shape of a magnetic field can be seen by using tiny, powderlike pieces of iron, called iron fillings. I think this was one of the children’s favourites ? !
Iron fillings like those on the end of the magnet in the above photo, reveal the lines and strength of the magnetic force. On a bar magnet, they line up to show how the magnetic force spreads out from the poles (ends).
A magnet has two ends called poles, one of which is called a north pole or north-seeking pole, while the other is called a south pole or south-seeking pole.The north pole of one magnet attracts the south pole of a second magnet, while the north pole of one magnet repels the other magnet’s north pole. So we have the common saying: like poles repel, unlike poles attract.
A magnet creates an invisible area of magnetism all around it called a magnetic field.
The north pole of a magnet points roughly toward Earth’s north pole and vice-versa. That’s because Earth itself contains magnetic materials and behaves like a gigantic magnet.
If you run a magnet a few times over an unmagnetized piece of a magnetic material (such as an iron nail), you can convert it into a magnet as well. This is called magnetization.