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Rules/Instructions:

• You may work with others in the class on this exam. But, if someone helped you with a problem, I expect to see that person's name listed on that problem. If you did most of your work in a group you can just put the group names on the first page.
• Group work does NOT mean: divvy up the problems, Xerox them at kinko's, staple together, and turn it in. If I feel something like this occurred I will average all your scores and give everyone that score, divided by how many people were in the group. Group work means: determine the correct answer together, individually write up your explanation of that answer, and turn in individual assignments.
• Two opportunities will be given to work on this assignment in class: Tuesday, December December 10 and Thursday, December 19.
• You may ask me questions about the exam.
• You may ask other faculty members questions about the exam if you inform them that the question is regarding a take-home final in this class and you include their name on your exam.
• You may use any text, magazine, or other source which you find helpful -- However, you must list all such outside sources at the place in the exam their information was used.
• The exam must be turned in by 8:15 PM on Thursday, December 19, 1996 in Swain Hall West Room 221 (our usual room). Turning the exam in early is fine.
• All materials turned in must be legible, and neatly and obviously organized. If I have to hunt around for your answers it is the same as no answer at all.
• If you have poor penmanship you are strongly encouraged to word-process (or type, for the Luddites out there) your written answers.
• All written answers must be in understandable English and all answers must be complete sentences.
• Otherwise, all the usual homework rules apply.

How I will grade:

• I will look at all of the exams and find the best. Then I will find the worst. Then I will rank the rest in between. If your answers are merely correct you may find your exam ranked in the B's or C's because other class members did far superior work.
• In your solutions you must justify and explain all steps in your work, explaining any supporting science used in your explanations. This means: SHOW ALL WORK. If you don't, you will receive NO credit for that problem.
• In each answer you must carefully explain where you obtained the information necessary to answer the question. For example: If you had to use a globe, light, and ball to understand where the full moon rises, you must say so. If you don't, you will receive a reduced grade.

Problems about Home and History:

1. Making a scale model of the solar system. Following the steps below, you will lay out markers for the Sun and all the planets.

1a. Calculate the scale for your model of the solar system. It must be large enough that the distances between the planets are at least 10 cm. The longest hallway in Swain West is about 130 feet long but you can go over 200 feet if you don't mind an "s" turn in the middle. What is the reduction factor you used for your model? (A reduction factor is the number you use to reduce the actual size of the solar system to something that will fit within a hallway at Swain Hall)

1b. Lay out your model and show it to me. Have me initial here: _____. Groups of no more than two members may work on this together.

1c. Calculate the size of the Sun and the nine major planets using the same scale as used above.

1d. Using the same scale as you used in your model above, calculate where the following objects would be in your scale model: The Oort cloud The nearest star other than the Sun The center of the Milky Way

Open-ended History Questions. Merely correct answers may not get full credit if they are inferior to answers from your classmates.

2. Explain what the Greeks knew about the Earth, moon, Sun, and the stars in the sky.

3. What did Copernicus do? Why was his work rejected by both scientists and the Church?

4. What did Kepler do? Why was his work more easily accepted than Copernicus's?

5. What did Galileo do?

6. What did Newton do?

7. When Copernicus placed the Sun in the center of the solar system he was able to calculate how many AUs each planet was from the Sun. His measurements agree almost perfectly with the modern values. Show how did he did these measurements by showing two examples: Mars and Venus. Hint: Kepler's 3rd Law had not been invented yet.

Problem 8: Elliptical orbits

8A. Really draw an ellipse as shown in the text on page 45.

8B. On the ellipse you drew, carefully draw and label the following: The semi-major axis, the foci, a planet, the planet's star.

8C. Indicate on the ellipse where the planet goes the fastest and slowest.

8D. If the Sun's mass was reduced to 40% of the current mass of the Sun and the semi-major axis of Earth's orbit was 9 x 10⁷ km, what would be the period of Earth's orbit in earth days? I promise you the formula is in the book somewhere.

8E. How would you implement a calendar that was accurate for orbit period you got in 8D?

8F. Skip - do not do this problem

8G. What if we changed the rotation speed of the Earth? How would you measure the length of a day?

8H. What if we changed the tilt of the Earth to something like 35 degrees? How would this effect our seasons?

Problem 9: Spectroscope

On page 107 in your text are instructions on how to build a spectroscope. Using the diffraction grating material I give you, do all of part 1 of the instructions.

Problem 10: The Solar System

10A. What are the observed properties of our solar system? As part of your answer make an accurate graph of the density of each planet versus its location from the Sun.

10B. How does the current explanation of the formation of the solar system explain the observed properties of the solar system?

Problem 11: Fun Stuff

11A. If you weigh 100 lb. On Earth, what would you weigh on Mars's moon Deimos?

11B. If you are standing on Deimos and can throw a baseball 60 mph, can you throw it completely off Deimos?

11C. Why do eclipses occur? Why don't they happen every four weeks?

11D. What change(s) would cause lunar eclipses to happen twice as often? There are lots of correct answers to this.

11E. If the typical killer asteroid is traveling 30 km/sec, how long would it take for such an asteroid to reach Earth from the Asteroid Belt?

11F. Most such asteroids would not be detected until they were within about one-half the distance between the Earth and the Moon. How long would it take for the asteroid to cover that distance?

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