World Library  
Flag as Inappropriate
Email this Article

Newton's cannonball

Article Id: WHEBN0005646168
Reproduction Date:

Title: Newton's cannonball  
Author: World Heritage Encyclopedia
Language: English
Subject: Isaac Newton, Early life of Isaac Newton, List of things named after Isaac Newton, Orbit, Newton Cannon
Collection: Isaac Newton, Space Guns, Thought Experiments in Physics
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Newton's cannonball

Newton's cannonball was a thought experiment Isaac Newton used to hypothesize that the force of gravity was universal, and it was the key force for planetary motion. It appeared in his book A Treatise of the System of the World.[1]

Contents

  • Thought experiment 1
  • Other appearances 2
  • See also 3
  • Notes 4
  • External links 5

Thought experiment

In this experiment from his book (p. 5-8),[1] Newton visualizes a cannon on top of a very high mountain. If there were no forces of gravitation or air resistance, the cannonball should follow a straight line away from Earth, in the direction that it was fired. If a gravitational force acts on the cannonball, it will follow a different path depending on its initial velocity. If the speed is low, it will simply fall back on Earth. (A and B) for example horizontal speed of 0 to 7,000 m/s for Earth.

Speed of cannonball at 0 m/s launched horizontally from newton's very tall mountain.
Speed of cannonball at 6,000 m/s launched horizontally from newton's very tall mountain.

If the speed is the orbital speed at that altitude, it will go on circling around the Earth along a fixed circular orbit, just like the moon. (C) for example horizontal speed of at approximately 7,300 m/s for Earth.

Speed of cannonball at 7,300 m/s launched horizontally from newton's very tall mountain.

If the speed is higher than the orbital velocity, but not high enough to leave Earth altogether (lower than the escape velocity), it will continue revolving around Earth along an elliptical orbit. (D) for example horizontal speed of 7,300 to approximately 10,000 m/s for Earth.

Speed of cannonball at 8,000 m/s launched horizontally from newton's very tall mountain.

If the speed is very high, it will leave Earth in a parabolic (at exactly escape velocity) or hyperbolic trajectory. (E) for example horizontal speed of approximately greater than 10,000 m/s for Earth.

Speed of cannonball at 11,200 m/s launched horizontally from newton's very tall mountain.

Other appearances

  • An image of the page from the System of the World showing Newton's diagram of this experiment was included on the Voyager Golden Record[2] (image #111).

See also

Notes

  1. ^ a b Newton, Sir Isaac (1728). A Treatise of the System of the World. London: F. Fayram. Retrieved 2 June 2014. 
  2. ^ Sagan, Carl et al. (1978) Murmurs of Earth: The Voyager Interstellar Record. New York: Random House. ISBN 0-394-41047-5 (hardcover), ISBN 0-345-28396-1 (paperback)

External links

  • Bucknell.edu – Astronomy 101 Specials: Newton's Cannonball and the Speed of Orbiting Objects
  • Drawing in the 1731 (2nd) edition of 'A Treatise of the System of the World' @ Google books
  • Newton's Cannon animation
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.