Homework Assignment 11
Due Nov. 7, 1997

1. Problem 4.13 from the text.

2. Problem 4.14 from the text.

3. Problem 4.15 from the text.

4. Problem 4.16 from the text.

5. Problem 4.17 from the text.

6. Problem 4.20 from the text.

7. Problem 4.21 from the text.

8. The maximum current recorded in a lightning strike is about 200 kA. This current flows for about 100 microseconds. If all of this current is carried to ground by a copper wire, what minimum diameter of wire should you use to make sure the temperature of the wire does not increase by more that 150^oC (so the wire will not be damaged)? The specific heat of copper is 0.39 J/g C^o. The density of copper is 9 g/cm³.