Homework Handout #14

14.01: Approximately how many times has the Sun circled the center of the Galaxy since the star's formation about 5 billion years ago?

14.02: Using the equation for density of dark matter given in the lecture notes, estimate the mass density of dark matter in the solar neighborhood.  What velocity should you use in this equation?  Express your dark matter density in units of g cm-3, Msun pc-3, and Msun AU-3.  How does your answer compare with an estimate of the stellar mass density in the solar neighborhood?