Physics 9 The Solar System with Prof. D. Tytler Oct. 2000

Homework 5, due Nov 9 in class

Note: second midterm is on Nov 14, Tue. Same style as first midterm.

We encourage you to work together, to discuss the topics and solutions, but your answers must use all of your own words, calculations and diagrams.

You must not hand in work copied from someone else.

Please write down the code numbers of all in your study group.

The first two problems are to encourage you to categorize information in preparation for the second midterm. The others encourage you to examine and absorb your class notes, except the last, which deals with the question: how do we learn about planets.
  1. Make a table which compares and contrasts comets, asteroids and meteoroids, in terms of mass, age, size, orbits and composition.
  2. As question 1, but for the terrestrial planets.
  3. Why do we not expect many comets or asteroids with circular orbits at distances between 5 and 30 AU from the Sun?
  4. Why do we expect small moons, asteroids and comets to lack volcanoes and (earth)quakes?
  5. What’s the difference between a long period comet and a member of the Oort cloud?
  6. How long is the lunar day? Night?
  7. Why was the rate of impacts much higher when the solar system was young?
  8. If in the distant past, the impact rate was 10,000 times higher than the current level, estimate the rate at which 20 kiloton, 50 Megaton, 1 Gigaton (Giga = 109) and 1 Teraton (Tera = 1012) impacts occurred. Use values given in Lecture 11. Rates will be number per unit time. Choose units of time such that the rates are always of order unity (e.g., 1 per hour, rather than 30 per day).
  9. Your car radio tuner breaks, and can only pick up 101.5 Megahertz. If you want to hear 105.3 Megacycles, what should you do? If you want to hear 95.7 Megahertz, what should you do?
  10. When are tides highest?
  11. A billion years from now will one year contain more than, less than, or exactly 365 days?
  12. There have been many missions to Mars. Pick one. Summarize the mission. Which scientific instruments were on the satellite? What were the scientific goals? What was learnt