Ch 1 – What Are Magnets http://www.sodahead.com/ By Mrs. Horvath

Properties of Magnets Magnet – an object that attracts, or pulls on, certain materials made of iron and steel Magnetism – a magnet’s property of attracting metal http://totalwealthcoaching.com/wp/wp-content/uploads/2009/05/magnet.png

Two Kinds of Magnets Permanent Magnets Keeps its magnetism for a long time Made in a factory Ex: refrigerator magnet Temporary Magnets don’t keep its magnetism for a long time Ex: nail stroked with a permanent magnet http://crafts.preschoolrock.com/uploads/images/Finished%20Magnets.jpg http://www.all-science-fair-projects.com/phase2/app/webroot/files/image/387/nail2.gif

North and South Pole North Pole – one end of a magnet always points north (called north-seeking) South Pole – one end of a magnet always points south (called south-seeking) http://commons.wikimedia.org/wiki/File:Bar_magnet.jpg

Attract & Repel Unlike poles  ATTRACT Like poles  REPEL http://www.ngfl-cymru.org.uk/vtc/ngfl/science/107/PP-electricity.html

Maglev Trains Mag = magnetic Lev = levitation (rise or float in the air) Goes fast Quiet and smooth (no friction) - friction – force caused by two surfaces rubbing against each other Eco-friendly (doesn’t pollute) http://www.dodevice.com/wp-content/uploads/2008/03/maglev-train.jpg

Force Fields Lines of Force Formed by iron filings Shows how force field spreads between the poles of a magnet Strongest / heaviest at the poles Magnetic Force Space in which the force of a magnet can act

Properties of Magnets Attract objects made of metal (iron or steel) Force is strongest/greatest at the poles (N or S) Like poles - - - > REPEL (push away) Unlike/opposite poles - - - > ATTRACT (stick)

Earth as a Magnet Earth is a giant magnet! Lodestone Naturally magnetic rock Found near Earth’s surface Discovered 2,000 years ago Chinese sailors used to make 1st compass Compass Magnetized needle that swings freely Points NORTH

Earth’s Magnetism Earth’s center – made up of IRON Earth spins on its AXIS (cause)… has magnetized the iron inside (effect)

Earth’s 2 Sets of Poles Earth has 2 sets of poles Geographic Pole – end of the imaginary line (AXIS) around which the Earth spins (ROTATES) Magnetic Pole – 1,000 miles from the geographic pole

Magnetism Lights Up the Sky Northern / Southern Lights Display bright colors in sky Auroras Particles of matter in space attracted to Earth’s magnetic field (giant magnet) Particles collide (crash) together & display light Earth’s force field strongest at the poles so more lights are seen there

What I Know Pick up metal Two of same poles can’t attract Opposite poles attract Different sizes & shapes (ex: bar magnets) What I Want to Know Pick up metal Two of same poles can’t attract Opposite poles attract Different sizes & shapes (ex: bar magnets) What I Learned