Magnets Huddleston Elementary 3 rd Grade

What do you already know about magnets?

What is a magnet? O Magnet- a type of metal that is attracted to iron O Iron- a magnetic metal; pure white in pure form, but rusts easily O Where have you seen or used magnets? Picture of pure iron Pictures of magnets

What does “attract” mean? O Attract- to pull towards each other O Anything that is attracted to a magnet is magnetic. O A magnetic object contains iron. O Do you know the antonym for attract? O Repel- to push away from each other Is this magnet attracting or repelling the metal objects?

What does “attract” mean? (cont.) O Magnets have a magnetic field. O Magnetic field- an area around the magnet where the magnet’s force can act O The closer a magnetic object gets to the magnetic field, the attraction is stronger. O The further a magnetic object is, the weaker the attraction.

Do you know the saying “opposites attract”? O Magnets have two poles: N (north-seeking) and S (south-seeking) O The N pole of a magnet is attracted to the S pole of another magnet. O The N pole of a magnet repels the N pole of another magnet. O What do you think will happen if you put a S pole of one magnet and another S pole of another magnet together?

Correct! O Like the two N poles, the two S poles will repel each other!

Attract or Repel? (click to find out!) a) attract b) attract c) repel d) repel

What do we use magnets for?

Uses of Magnets: daily life

Uses of Magnets: natural magnets Magnetite: a magnetic mineral Lodestone: a form of magnetite that has N and S poles

Uses of Magnets: compass O Quick review: What is a compass? O So how does a compass work???

How does a compass work? O The Earth has a magnetic field which has the force that goes out into space. O The magnetic needle on the compass detects the Earth’s magnetic field and lines up with the magnetic field.

Uses of Magnets: electromagnets O Electromagnets: magnets powered by electricity. O Electromagnets can be turned on or off. O When the electricity is flowing, the magnet will attract things with iron. O When the electricity stops, the magnet stops working. O Because it can be turned on and off, electromagnets are temporary magnets.

Electromagnets (cont.) O Here’s a simple electromagnet: O The nail becomes a magnet when the electricity runs through the coil! O Let’s look at a more complex electromagnet

These electromagnets are helpful when you need something extremely heavy moved! They are also used in building (moving metal beams into place), moving cars in junk yards, and recycling (removing scrap materials).

Electromagnets are also found in… Maglev (magnetic levitation) trains hard disc drive (computer)

Uses of Magnets: generators O Generators: a machine that creates electricity by using magnets. O The opposite of electromagnets O We won’t get into the deep details of how generators work… That’s big kids science! Generators are useful when the power goes out at your house during a storm. It can create electricity for you!