Lesson 7 the power of magnetsPresentation Transcript
The power of magnets Lesson 7
Magnetism Is a force of attraction or repulsion that acts at a distance. It is due to a magnetic field, which is caused by moving electrically charged particles or is inherent in magnetic objects such as a magnet. A magnet is an object that exhibits a strong magnetic field and will attract materials like iron to it. Magnets have two poles, called the north (N) and south (S) poles.
Attraction When two magnets or magnetic objects are close to each other, there is a force that attracts the poles together. Force attracts N to S Magnets also strongly attract ferromagnetic materials such as iron, nickel and cobalt.
Repulsion When two magnetic objects have like poles facing each other, the magnetic force pushes them apart.
Magnetic materials Magnets can attract other magnets but they can also attract magnetic materials. The magnetic materials are always metals but only a few metals are magnetic. Iron is magnetic, so any metal with iron in it will be attracted to a magnet. Steel contains iron, so a steel paperclip, for example, will be attracted to a magnet.
Most other metals, for example aluminium, copper and gold, are NOT magnetic. An aluminium drinks can, for example, will not be attracted to a magnet. http://www.youtube.com/watch?v=2vqgXRKHI-s&feature=related
Game http://www.funny-games.biz/magnetism.html http://www.candystand.com/play/magnets http://www.bbc.co.uk/schools/scienceclips/ages/7_8/magnets_springs.shtml