1. Week 5: Magnetism October 16th, 2015 Katie Hellier IRIS Science Academy

2. Last Week Electric Fields Where do they come from? How do they work? What effects do they have on us?

3. Magnetism Moving charges interacting with moving charges Ex: two wires Electro-magnetic interactions are linked Magnetic forces are electrical forces in a different frame of reference (relativity) Comes from what the material is made of (atoms, structure)

4. How does it work? Think about electricity – attraction vs repulsion

5. Video Bill Nye the Science Guy

6. Magnetic Fields B ~ I Units: T (Tesla) Create the force exerted on a charge due to magnetism Field lines move from North to South Objects align along field (ie compass) Magnetic poles are where field lines start and end Direction – Force is perpendicular to both the magnetic field and direction of motion

7. Earth’s Field Molten Iron core Field keeps radiation and solar winds out Creates Aurora Borealis Like to bar magnet Why is North actually South?

8. Video The Science Behind Magnets

9. Different Types of Magnets Ferromagnetic: Permanent magnet – creates own field, is attracted to other magnets Paramagnetic: Temporary magnet – attracted by an external field, goes away Electromagnets: Adjustable magnets created by running current through a coil of wire

10. Phets Magnet and Compass Magents and Electromagnets

11. Magnetism Lab Mapping the magnetic field Pick a partner Select a magnet Work with the table to graph the magnetic field