1. Week 4: Electric Fields October 9th, 2015 Katie Hellier IRIS Science Academy

2. Last Week Circuits What are the components? What are the characteristics? What is Ohm’s Law? What is a diode? How does a superconductor work?

3. Electric Fields Energy field created by matter Creates the electric force on objects Not something we can see Represented as a wave

4. Electric Fields Moves away from positive charge, towards negative Use arrows to represent strength of field and direction

5. Phet/Video Video – Electric Field Visualized Phet – Charge and Fields

6. Measuring E-Fields Define by the force created on a “test” object (positive charge) at some point  Tells us what the field should be at any point with/without test object QQ E q+ d

7. Sources and Sinks Source – flows out of Sink – flows into Compare to gravity

8. Video MIT Physics Demo – Faraday’s Cage What’s in a Candle Flame?

9. Lightning Clouds undergo charge separation  Causes surface of the earth to become polarized Electric field is created  ionizes air, creates plasma – very conductive! Electrons race to earth, releasing light and energy

10. Lab – Plasma Orbs How do they work? Light an LED How far away can you get it to work? In what direction? Measure the potential What gives you the greatest V? What do you notice about it? Short Circuit How can you disrupt the flow? Increase it? Stabilize the plasma thread Where on the ball can you get a stable thread? Why do you think this is? Create Lightning Use a penny or aluminum foil – can you figure out how to create a spark?