Unit 3 : Activity 3 : Inventory of the Solar System : Figuring Out Solar System Distances : Unit Exam

Unit 3: End of Unit Exam

This assignment consists of four parts. The first is a review with a couple of practice questions linked directly to their answers. The second is a short quiz that you take using Blackboard. It will be instantly scored for you by Blackboard; you only get one chance to take it, however, so be sure you are ready! The third part is an essay question. The question appears below; when you are ready to answer it, log on to Blackboard and submit your essay. Finally, for each unit, you should log on to Blackboard and contribute a question, an answer, or a comment to one of the posted topics. If you would like to introduce a new topic instead of contributing to an existing thread, please send your topic idea to your instructor. If you find the material in this unit challenging, you might want to start with the "discussion" part of the assignment in order to get some help with some of the ideas.

To use Blackboard you will need to be signed up as a student in the course. That means that first you must enroll for credit and then you can login to Blackboard. The instructor will verify that you are enrolled in the course and verify your enrollment in NorthStar.

Brief summary of Unit Three:

First, we gave an inventory of the planets in the Solar System. We also described how one can determine the distances to the other planets in terms of the Earth-Sun distance.

Before you go to the quiz, see how you do on these two questions. If you have trouble, you might want to review the unit, send a question to the discussion group, or seek help from the instructor.

Practice Question One

The planets are uniformly spaced in their mean distances from the Sun. True or False? Explain.

Practice Question Two

To determine the absolute size scale of the Solar System, is it enough to plot the motions of the planets against the backgound stars in the night sky over several years? Why or why not?

When you are ready, login to Blackboard and take Quiz Three.

You will get instant feedback on your score on Quiz Three (and your instructor will also be informed of your score). If your score is OK, you may proceed directly to the Essay Question Three on Blackboard. Otherwise, you might want to look at what you missed, ask your instructor about questions you missed, or review relevant parts of the unit.

Essay Question

A. Why is it difficult to present a picture of the solar system with both the planets and their separations shown to the correct scale? If you are stuck, try part B first.
B: The diameter of the Earth is 1/100 the diameter of the Sun and there are about 100 Sun-diameters between Earth and the Sun. If you make the Earth the size of a peppercorn (about 1/10 inch or 1/4 cm across) how big does your piece of paper need to be to also include
the Sun?) If you need help setting up the calculation, check this "help" button.

Don't forget to contribute to the discussion on Blackboard on one of the topics in this unit!