1. Do Now (2/5/14) Do not touch the materials on your desk until instructed to do so. 1) Are all metals magnetic? 2) Can non-magnetic materials interact with magnets?

2. Intro to Electromagnetism

3. Copper Tube Demo You will have 10 minutes to complete the Demo Activity. Do not drop the magnets on the floor! Please ignore air resistance in your answers.

4. Copper Tube What did you observe when you dropped your pencil? What did you observe when you dropped the magnet? Was the magnet attracted to the copper tube? What guesses did you come up with for why this occurs?

5. Electric Current and Magnetism In 1820, it was hypothesized that the electric current must produce a magnetic field around the wire. Michael Faraday wondered if the reverse might be true!?!

6. Energy Transfer What type of energy transfer is this? Kinetic Energy to Electrical Energy He discovered that he could induce current by moving a wire through a magnetic field

7. Inducing a Current It is the relative motion between the wire and the magnetic field that produces a current. What if the wire moved parallel to the Magnetic Field? Would current be produced? NO CURRENT IS PRODUCED IF THE WIRE MOVES PARALLEL TO THE MAGNETIC FIELD

8. Current What sort of shape do magnetic field lines form around a current carrying wire?

9. Exit Question: A wire of length 10 cm moves parallel along a magnetic field of strength 8T such that none of the field intersects the wire. If the wire is moving 500 m/min what is the resulting current through the wire?

10. Do Now (2/6/14) 1. What must be true for a current to be induced in a wire as the wire moves through a magnetic field? 2. A uniform magnetic field B, with magnitude B = 1.2 x 10 -3 T, points vertically upward throughout an enclosed space. A proton with a velocity v = 3.2 x 10 7 m/s enters the space moving horizontally from south to north. Find (a) the magnitude and (b) the direction of magnetic field.

11. Lets Change Gears What is the direction of centripetal force? Towards the center of the circle What is the name of a force acting on an object that moves in a circular path?

12. Mass Spectrometer o Measures the mass of an unknown atoms or molecules

13. RHR Why does the particle curve downwards?

14. Radius of the Circle Name the two forces in the diagram Magnetic force == centripetal force Lets solve for the radius of the circle:

15. Identify our Variables m = Mass v = Velocity q = Charge B = Magnetic Field Strength r = Radius

16. Apply RHR Is this particle an electron or proton? Proton RHR How do we know if this particle is an electron or proton?

17. Moving through a Voltage V = voltage v = velocity Q = Charge M = Mass

18. Classwork Use the rest of class time to work on your homework. ‘Interaction between E and B and matter’

19. Do Now (2/7/14) An electron moves at 4.2 x 10 5 m/s as it passes through a magnetic field. What is the radius of it’s circular path?

20. Electricity What are different ways we generate electricity? Hydro-electric Dams Wind Power Generators Solar Power Fossil Fuels What type of energy transfer is this? Kinetic Energy to Electrical Energy

21. EMF A current is induced A force is exerted on the charges in the wire. This increases the electric potential energy on the charges. What occurs if a wire moves through a magnetic field?

22. EMF What have we learned before that uses the word ‘potential’? Potential Difference! (ΔV) This change in potential, or potential difference is called the induced electromotive force, or EMF.

23. Electromotive Force (emf) - IS NOT A FORCE o It was defined before we fully understood electricity. o Think of it as a voltage. The EMF (ε) is measured in volts and depends on: ε = B l v Where l is the length of the wire. EMF

24. Classwork Use the rest of class time to work on your homework. Either: ‘Interaction between E and B and matter’ Or ‘Electromagnetic Induction’

25. Cool videos Feel free to watch these on your own time http://www.youtube.com/watch?v=txmKr69jGBk magnet: http://www.youtube.com/watch?v=FM3LVrKXFcA