Magnets SPI Success Criteria:

Transcription

1 Magnets SPI Distinguish among the Earth s magnetic field, a magnet, and the fields that surround a magnet and an electromagnet. Success Criteria: 1. I can explain the properties of any magnetic field. 2. I can identify a properly illustrated magnetic field.

2 Remediation Assignment You MUST record 2 points from each slide with written information You will not write anything from the slides containing ONLY pictures There are 12 slides with written information for you to record in your remediation sheet (HINT: this mean you write a total of 24 points

3 Magnets Any material that attracts iron (Fe) or anything that contains iron (Fe) Two poles (North and South) The poles are strongest near the ends Exert forces on each other Surrounded by a magnetic field

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5 The Poles How do you label the North and South Poles? Hang a magnet from a string and the North pole will always point north. Poles always come in pairs

6 Forces Magnets have forces they exert on other magnets When 2 magnets are close together they will either push or pull each other This happens b/c of spinning electric charges inside the magnet Universal force Like poles repel and opposites attract

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8 Fields A magnetic field is around a magnet where the forces can act The closer together to field lines are the stronger the magnetic field is The lines will be closest at the poles Where will the magnetic field be the strongest on a magnet?

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10 The Cause Whether a material is magnetic depends on its atoms Electrons spinning around the outside of the atom form a small and weak magnetic field Ni, Co, and Fe the atoms form in groups called domains These domains line up forming North and South Poles

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12 Unaligned When the domains are not lined up, the magnet looses it magnetism Dropping or hitting a magnet hard can move the domains Increasing the temperature can cause the lose of magnetism Placing the magnet in a strong magnetic field opposite can cause the domain to be misaligned

13 Making Magnets Rub a piece of Fe, Co,Ni with a magnet Use one pole of the magnet to align the domains in the metal Ex) iron nails can easily be turned into magnets Temporary magnets can be made when an object is attracted to a magnet. While the object is still connected, the domains in the object line up making a temp magnet

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15 Cut a Magnet Cut a magnet and you will end up with 2 magnets Each magnet will have a North and South pole Very small magnets will have North and South poles

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17 Magnet Types Ferromagnets: naturally occurring magnets usually made from Fe, Ni, Co Temporary: materials that are easy to magnetize, but also loose their domains easily Permanent: harder to magnetize but will keep their domains aligned longer Electromagnet: made by an electric current using an Fe core

18 Earth Earth is surrounded by its own magnetic field Imagine a giant bar magnet inside Earth Compass needles work because the Earth s magnetic field The north pole of the compass needle points towards the Earths north pole (Santa s House) How does the compass s North pole point to the Earth s north pole? (hint opposites attract)

19 Earth s Geographic North Pole and Magnetic South Pole Earth s Geographic South Pole and Magnetic North Pole

20 Earth s Field Earth does not have a bar magnet through its center The Earth s core is solid, but the outer core is liquid As the Earth rotates, it cause the outer core to flow Electrical charges moving around the outside of the core cause a magnetic field

21 Purpose of the Field What does Earth s magnetic field do for us? Protects the Earth s ozone layer Ozone layer protects from sun s UV rays Auroras borealis (northern lights) cause by charged particle from the sun reacting with O and N in our atmosphere Gaps in the magnetic field near the poles allows small amounts of particles in Auroras australis (southern lights)

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