Answer any four of the following questions in as much detail as possible.

1. Models are particularly useful in relativity and quantum mechanics, where conditions are outside those normally encountered by humans. What is a model? How does a model differ from a theory?

If two different theories describe experimental observations equally well, can one be said to be more valid than the other (assuming both use accepted rules of logic)?

3. Can the validity of a model be limited, or must it be universally valid? How does this compare

4. Can classical physics be used to accurately describe a satellite moving at a speed of 7500 m/s? Explain why or why not.

5. What is the relationship between the accuracy and uncertainty of a measurement?