1. Measurements show that there is an electric field surrounding the Earth. Its magnitude is about 100 N/C at the Earth's surface and points inward toward the Earth's center. From this information, can you state whether the Earth is negative or positive?

Question

(Planet Earth is negatively charged, Planet Earth is electrically neutral, Planet Earth is positively charged or There is not enough information to decide.)
2. If you are caught outdoors in a thunderstorm, why should you not stand under a tree? Can you think of a reason why you should not stand with your legs far apart? Or why lying down can be dangerous? (Hint: Consider electric potential difference.)
3. If you rub an inflated balloon against your hair and place it against a door, by what mechanism does it stick? Explain.
4. When the chassis of a car is moved into a painting chamber, a mist of paint is sprayed around the chassis. When it is given a sudden electric charge and mist is arracted to it, presto - the car is quickly and uniformly painted. What does the phenomenon of polarization have to do with this?

Answer 1

Give them a try, and I will be happy to critique.

On the first one, Earth is mainly an insulator.