Astro101V: Midterm I

Name:

This is a take-home exam, and is due on or before Tuesday, Feb 2, 1998 AT THE BEGINNING OF THE CLASS PERIOD. This deadline is firm, and I will not accept exams handed in after 7:15 pm on Tuesday, Feb 2.

You may use your class notes, or information out of your own head, or the textbook, but using information out of other people's heads is bad form and WILL NOT BE TOLERATED. Remember that if I can't decipher what you've written, I can't give you any credit! Also, remember that a picture or diagram is often worth athousand words, and a thousand hours of thought...

If you have a question about the meaning of one of the questions, feel free to e-mail me: palen@astro.washington.edu , or to call me in my office: (206) 543-2604. I may not be able to answer your question, but it's worth a shot.

Midterm I

  1. (5 points) At what lunar phase can a solar eclipse occur? At what lunar phase can a lunar eclipse occur? Explain why we do not have a solar and lunar eclipse each month.
  2. (5 points) Draw a picture of the Sun-Moon-Earth system during a spring tide. During a neap tide. Be sure to indicate the tides on the Earth.
  3. (5 points) Name 4 astronomical motions that occur during the course of one day. For each of these, give one observable consequence of the motion.
  4. (5 points) Name two types of optical detectors. Give a pro and a con for each type.
  5. (10 points) What would the length of the solar day be if the Earth orbited the Sun at twice its current rate (so that 1 year = 182 days)?
  6. (15 points) Are all kinds of radiation equally harmful? Why or why not? Arrange the following items in order of their harmfulness to you, personally.
    1. bullets from a gun
    2. gamma rays
    3. radio waves
    4. visible light
    5. a fast ball
    6. children who've had too much sugar
  7. (10 points) Suppose that you wanted to know the total velocity of a star---Sirius for example. How would you find it? Be sure to explain how you would find both parts of the velocity.
  8. (10 points) The spectrum of a star contains three vital types of information. What are they, and how do you determine them from the spectrum?
  9. (5 points) What is your instructor's least favorite thing about the magnitude scale? (This is not a trick question!)
  10. (5 points) Make up a new mnemonic for OBAFGKM...
  11. (5 points) List the planets in our Solar System, in order outward from the Sun. Give one unique fact about each of them. (1st from the Sun, 2nd from the sun, etc. is a flippant answer, and you will get no credit!)
  12. (20 points) Your plane gets hijacked! The hijackers fly the plane for some indeterminant amount of time---it's hard to tell time when you are so stressed out... Finally, the plane lands, and all of the passengers are herded outside. You want to know where you are, and you look up in the sky for a clue. You look around, and find the North Star just barely above the horizon. The third quarter moon is just rising in the East. Very sneakily, you take out your satellite phone, and call your mom in Seattle. You ask her one question. She replies, ``You're lucky you caught me, I was just about to go eat lunch... I don't know where it is. Let me go see.'' She comes back to the phone after a moment and says ``On the horizon.'' You tell your mom where you are, and she calls THE AUTHORITIES. Everyone is rescued and you are a big hero! What was the question, and where are you relative to Seattle? Explain your reasoning, and don't forget how useful a picture can be!