Astr 345 Assignment 5
Due before midnight Fri, Sep 26, 2008 (full credit), before midnight Fri Oct 3, 2008 (half credit)
1. Hartmann, chapter 3, problems 3,4,12,14,15,20
2. (i) Assuming circular orbits, find the orbital velocity of the Earth around the Sun, and of the Moon around
the Earth. These orbits are close enough to circular that computing the circular velocity is a reasonably
close approximation to the actual speed. (ii) Find the escape velocity from the surface of the Earth, and
of the Moon.
3. Find the center of mass (CM) of (i) the Sun-Jupiter system, and (ii) the Earth-Moon system.
4. (i) Find the distance (center-to-center) of a geostationary satellite in orbit about the Earth. Express your
result in terms of the Earth’s radius. (ii) If the satellite appears to be stationary to an Earth-bound
observer, then what is the inclination angle, i, of the orbit of the satellite?
5. Mercury is viewed at its maximum elongation of 28◦. What is Mercury’s distance from the Sun (in AU)
when viewed in this circumstance?
Grading:
•You can share concepts, but all work must be completely original
•Write neatly and legibly
•Line up equal signs in a straight vertical column, and never have more than one equal sign on a line
•Define all non-standard variables
•Do not skip essential lines of algebra
•Develop ideas logically from start to finish
•Include a statement at the end of each problem interpreting the result
•Label your diagrams; all plots must be computer plots
•Take pride in your work
•All assignments are out of 30 points
