9.19  

1. Suppose you imbedded some free charge in a piece of glass. About how long would it take for the charge to flow to the surface?

2. Silver is an excellent conductor, but it's expensive. Suppose you were designing a microwave experiment to operate at a frequency of 10¹⁰ Hz. How thick would you make the silver coatings?

3. Find the wavelength and propagation speed in copper for radio waves at 1 MHz. Compare the corresponding values for air (or vacuum).