1. MAGNETISM

2. Magnet Describe in your own words what a magnet is and does.

3. Magnetic Field The Earth itself is a magnet Its magnetic poles are almost 2000 km from its geographic poles North and South magnetic poles produce magnetic forces North and South poles ALWAYS occur in pairs Like poles repel; Opposite poles attract

4. Earth’s Magnetic Poles

5. Earth’s Poles Earth’s poles move slowly with time Measurements of magnetism in rocks show that Earth’s magnetic poles have changed places over 150 times in the past 70 million years Many scientists believe iron and nickel in Earth’s core produces the magnetic field Others believe that rising convection currents play a role

6. Magnetism Explore and describe uses of magnets Identify the poles of a magnet Identify the description of a magnetic field

7. Magnets A magnet will pull some metals towards itself. Metals that contain iron, nickel, and cobalt are magnetic. In other words, a magnet will pull them.

8. We use magnets in many ways! Which of the following items in a home use a magnet? Blenderwasherdryer Radiocan openerdishwasher Refrigeratordoorbellcompass Click here to find out! ( select kitchen on the left of the screen, close window to return to this presentation ) http://www.fossweb.com/modules3- 6/MagnetismandElectricity/index.html http://www.fossweb.com/modules3- 6/MagnetismandElectricity/index.html

9. Uses of magnets Magnets were first put to use in navigation because they always point north and south. Magnets are used to hold, separate, control, convey and elevate products and to convert electrical energy into mechanical energy or convert mechanical energy into electrical energy.

10. Magnets around the House: Headphones Refrigerator magnets Computer speakers Telephone receivers Phone ringers Microwave tubes Seal around refrigerator door Plug-in battery eliminators Floppy disk recording and reading head Audio tape recording and playback head Video tape recording and playback head Credit card magnetic stripTV deflection coil Computer monitor Computer hard drive Shower curtain weights / attach to tub Power supply transformers

11. Magnets inside of motors: CD and DVD spinner and head positioner Audio and VHS tape transport VHS tape loaderMicrowave stirring fans Kitchen exhaust fansGarbage disposal motor Sump pumpFurnace blower and exhaust Garage door openerBathroom exhaust fan Electric toothbrushCeiling fan Pager or cell phone vibrator Clocks (not the wind-up type or LCD type) Computers

12. Magnets in your Car: Starter motor A/C clutch Interior fan motor Electric door locks Windshield wiper motor Electric window motor Side-view mirror adjuster motor CD/tape player motor and playback Engine speed sensors Alternator Starter relay Windshield washer pump motor

13. Magnets have Poles Just like the Earth has a North and South Pole, magnets also have two poles. If you take a bar magnet and hang it from a string, the end that points north is the magnet’s North Pole, and the end that hangs south is the South Pole. This is because the Earth is actually a HUGE magnet itself! Similar magnetic poles repel, while opposite magnetic poles attract.

14. Magnets also have a Magnetic Field Every magnet has a magnetic field around it. It can be thought of as a line of force running from the north end of the magnet to the south end of a magnet. Earth’s magnetic field is what causes the needle of a compass to point north and south.

16. The following links can help you learn more about magnets: http://www.bbc.co.uk/schools/revisewise/science/ physical/12_fact.shtml click next after reading the facts to take a quiz!http://www.bbc.co.uk/schools/revisewise/science/ physical/12_fact.shtml Complete this activity to explore magnetic fields http://www.galaxy.net/~k12/electric/fields.shtml http://www.galaxy.net/~k12/electric/fields.shtml Ten facts about magnets: http://tm.wc.ask.com/r?t=c&s=a&id=30780&sv=za5 cb0dc7&uid=2d0b7690bd0b7690b&sid=3d0b769 0bd0b7690b&p=%2flinks&o=0&u=http://www.ex ecpc.com/~rhoadley/magbasic.htm