1. Static Electricity
In the wintertime, why do you get a shock when you touch a light switch or even another person or pet? Why do balloons cling to the wall at birthday parties? Can you describe the process called "induction" and explain how that relates to static electricity? Explain briefly how knowing about static electricity can help you understand other aspects of electricity?

Explore the links below to answer these questions.

Consider This Before Answering the Questions
Particularly in the wintertime, you may have noticed that touching light switches or even another person or pet can be quite a shocking experience. As noted in the text, this is especially a problem on dry days. You've also surely seen how balloons cling to a wall when you've created positive-charge regions.

• To see this in action, visit http://www.mcrel.org/whelmers/index.asp?option=404
• Click on Static Charged 2x4s - #31 and conduct the little experiment described there.
• When you get to the "Content topics," stop a moment and write down definitions for the four terms (static electricity, friction, attraction, and repulsion).
• Then go ahead and follow the instructions (remembering that you are the "student" and should answer the questions posed).
• Did you get the expected results?

After You Answer the Questions
The last paragraph of this section you've just read suggests that you "research and investigate lightning." Although this is jumping ahead to Chapter 20, see if you can apply what you've already learned about induction and electrical discharge.

2. Electromagnetic Waves
What are force fields? What role do vibrating charges play in electromagnetic processes? Can you visualize classical and electromagnetic waves? What do you know about lines of force?

Follow the links below to better understand the various terms and components of electromagnetic waves and how electromagnetism works. .

Consider This Before Answering the Questions
The text offers a lot of applications of electromagnetism, pointing out that it's "one of the most important aspects of physical science," and that it's the basis of much of today's technology. To understand electromagnetism, first it's important to understand electric forces.

• Check out http://www.colorado.edu/physics/2000/waves_particles/index.html for a clear understanding of the electric force" and electromagnetic waves. This is a bit of a "treasure hunt," but it's really worth the tangling road.
• Scroll down and click the "next" button and begin with the section on The Electric Force (clicking your mouse where indicated, then writing down definitions and explanations of what is going on.)
• Continue through the "Next" pages until you've completed that first session. Move on to the next section on "Force Fields" (very important to understand with respect to electromagnetic processes).
• Then go to "Vibrating Charges and Electromagnetic Waves." Again, click, drag, or otherwise participate as instructed, and jot down definitions and explanations, being sure that you can answer the questions (if you're not sure of your answers, go back and do the demonstrations again).
• As you vibrate down Vibrating Charges and Electromagnetic Waves, link to the "Classical Waves." Although it says you're leaving Electromagnetic Waves, actually you're not-you're going to "More about Visualizing Electromagnetic Waves." Work yourself down that site, seeing if you can answer the questions before the "professor" does. At the end of that section, hit "Next," and you'll wind up at the last session of this exercise, which deals with the lines of force.

After You Answer the Questions
Now that you're done, organize your notes and your thoughts to review the various terms and components of electromagnetic waves and how electromagnetism works. Based on what you learned, are there applications you can think of that weren't mentioned in the text? Can you extend what you learned into your own life to understand common and not-so-common items that you use?