Skip to ContentGo to accessibility page
OpenStax Logo
Astronomy 2e

Review Questions

Astronomy 2eReview Questions

Review Questions

1.

State Kepler’s three laws in your own words.

2.

Why did Kepler need Tycho Brahe’s data to formulate his laws?

3.

Which has more mass: an armful of feathers or an armful of lead? Which has more volume: a kilogram of feathers or a kilogram of lead? Which has higher density: a kilogram of feathers or a kilogram of lead?

4.

Explain how Kepler was able to find a relationship (his third law) between the orbital periods and distances of the planets that did not depend on the masses of the planets or the Sun.

5.

Write out Newton’s three laws of motion in terms of what happens with the momentum of objects.

6.

Which major planet has the largest . . .

  1. semimajor axis?
  2. average orbital speed around the Sun?
  3. orbital period around the Sun?
  4. eccentricity?
7.

Why do we say that Neptune was the first planet to be discovered through the use of mathematics?

8.

Why was Brahe reluctant to provide Kepler with all his data at one time?

9.

According to Kepler’s second law, where in a planet’s orbit would it be moving fastest? Where would it be moving slowest?

10.

The gas pedal, the brakes, and the steering wheel all have the ability to accelerate a car—how?

11.

Explain how a rocket can propel itself using Newton’s third law.

12.

A certain material has a mass of 565 g while occupying 50cm350cm3 of space. What is this material? (Hint: Use Table 3.1.)

13.

To calculate the momentum of an object, which properties of an object do you need to know?

14.

To calculate the angular momentum of an object, which properties of an object do you need to know?

15.

What was the great insight Newton had regarding Earth’s gravity that allowed him to develop the universal law of gravitation?

16.

Which of these properties of an object best quantifies its inertia: velocity, acceleration, volume, mass, or temperature?

17.

Pluto’s orbit is more eccentric than any of the major planets. What does that mean?

18.

Why is Tycho Brahe often called “the greatest naked-eye astronomer” of all time?

PreviousNext
Order a print copy
Citation/Attribution
Reuse and redistribution of this content in digital or print format:
  • This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's prior written permission.
  • This book uses the Creative Commons Attribution-NonCommercial-ShareAlike License, which means that you can reuse and modify the material only for noncommercial purposes, must attribute OpenStax, and must distribute any derivative works under the same license.
  • Any commercial printing of this textbook, including using a local or custom printer, must be approved by OpenStax, and proper citation provided.
  • OpenStax-copyrighted images, activities, assessments, and similar components of this book are subject to the same licensing – CC-BY-NC-SA. They can be used for noncommercial purposes with attribution. Commercial use requires permission.
  • Permission requests: Anyone who intends to incorporate this content (including text, images, and other components) into large language models, use it in AI offerings, use it commercially (including in print), and/or has questions about another use case is welcome to complete our reuse request form.
Attribution information
  • If you are redistributing all or part of this book in a noncommercial print format, then you must include on every physical page the following attribution:

    Access for free at https://openstax.org/books/astronomy-2e/pages/1-introduction

  • If you are redistributing all or part of this book in a noncommercial digital format, then for every page that includes OpenStax content, you must license the derivative work under the same CC-BY-NC-SA license as the original, and include on every digital page view the following attribution:

    Access for free at https://openstax.org/books/astronomy-2e/pages/1-introduction

Citation information

The information below includes the information needed to generate citations in most major styles (APA, MLA, etc.); you must reformat and organize the information as needed to fit the requirements of the style. Use the information below to generate a citation. We recommend using a citation tool such as this one.

© Jul 21, 2026 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike License. The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo, and Rice University name, and Rice University logo trademarks, or wordmarks are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.