Moving & Using Static Charge

1. Moving & Using Static Charge Text 10.1-10.2: Page 400-411

2. Agenda • Review of Static Charge • Moving Charge • Different Materials • Contact Charge • Induction Charge • Grounding • Electric Discharge • Electroscope Review Activity

3. Learning Goals • By the end of this class, we should be able to • Compare and contrast insulators and conductors • Compare and contrast static, contact and induction charge • Complete an investigation to test types of current charge and conductivity of materials

4. Reviewing Static Electricity

5. Materials • Materials can be grouped by weather they allow charge to move through them • Insulators and Conductors are groupings determined by their conductivity • Conductivity is the ability of materials to allow Martials to allow electrons to move freely in them.

6. Insulators • Material that hold onto their electrons and do not allow them to move easily are called electrical insulators • An insulator is a solid, liquid or gas that resists or blocks the movement of electrons • EX: dry wood, glass and plastic

7. Conductors • Materials that allow electrons to change positions are called conductors • Conduction is the movement or transmission of electrons through a substance • Ex. Copper and aluminum

8. Somewhere in the Middle? • Some materials only allow some movement of electrons • These are called fair conductors • Sort of like an insulator, sort of like a conductor • NOTE: only PURE water is an insulator • Most water has minerals in it so it is considered a fair conductor

9. Let’s Test It – Conductivity Test • Assemble the electrical conductivity apparatus. • Test conductivity of different samples.

10. How Can You Test For Charge? • You can use an electroscope • This is an instrument used to detect electric charge • Metal-Leaf electroscope has a two very thin metal pieces called leaves suspended from a metal rod. • The metal rod is then attached to a top plate or metal knob

11. What Would Happen If? +

12. What Would Happen If? -

13. Contact Charge • This is an example of Contact Charge • This can also be called charge by contact • The charge is made through contact with another charged object

14. Induction Charge • This is very similar to contact charge • Is the movement of electrons between objects close by but not in direct contact • EX: you can statically – charge a balloon by rubbing it on your hair • Put the balloon near a wall and it will attract to it! • No contact is made

15. Grounding • Grounding is the process of connecting a charged object to the earth’s surface • This creates a path for the electrons to travel to the ground • “Escape route” for electrons which removes charge

16. Electric Discharge • When electrons find an escape route and they transfer very quickly it is called electric discharge • Sparks are an example • Sparks are a transfer of charge by induction

17. Electric Discharge • Lightning is a very large example or electric discharge • Inquiry Question – Which way does a lightning bolt travel? http://www.youtube.com/watch?v=l9kVA6aY5P8

18. Electroscope Lab

19. Using Static Charge • Pick a group of 2-3(max.) • Choose a topic: • Lightning rods (p.g. 418) • Static charge on vehicles (p.g. 419) • Reducing static charge at home & work (p.g. 420) • Spray Painting (p.g. 421) • Photocopying (p.g. 422) • Enviromental Applications (p.g. 423) • Summarize your findings using words & text • Final Round = Static Charge Walk About