## Astronomy 161: Review Guide for Second Quiz

### Mechanics

Same as for the first quiz. The quiz will have 10 multiple choice questions, and it will occupy the first 20 minutes of Friday's class. If you're late, that's your problem ... in accordance with the makeup policy, you can only take a makeup quiz if you have notified me in advance that you will be absent. The quiz is closed book, but you may bring a single sheet (both sides) of handwritten notes. You may bring a calculator, but you will not need it. Please bring a number 2 pencil.

### Topics

The quiz will cover the material in Lectures 5-9 (i.e., through Wednesday's lecture). The reading for all of these lectures is chapter 4 of the textbook.

Names to know: Ptolemy (2nd Century AD), Copernicus (1473-1543), Tycho (1546-1601), Kepler (1571-1630), Galileo (1564-1642), Newton (1642-1727)
I don't expect you to know dates, but you should know the general order in which things happened, which is evident from the birth and death dates above: Copernicus developed his model first, Tycho carried out his observations later in the same century, Kepler and Galileo were contemporaries with Kepler building on Tycho's observations, and Newton worked after Kepler and Galileo had made and published their discoveries.

While there will not be any complicated calculations on the quiz or the midterm, we have by now covered several important equations. I expect you to understand the physical content of these equations and the ways that they can be applied, and to be able to do simple calculations with them (e.g., if I double the distance between two objects, what happens to the gravitational force between them?). The important equations through lecture 9 are:

• a = d x (theta / 57.3 degrees)
• P2 = a3
• F = m a
• F = G M1 M2 / d2
• (r / 1 AU)3 = (P / 1 year)2 x (M / Msun)