1 / 11

Universal Gravitation

Universal Gravitation. Chapter 8. 8.1 Motion in the Heavens and on Earth. Stars - regular path Planets - wanderers, complicated path Comets - more erratic path Galileo, Kepler, & Newton provided insight into how objects move.

jam
Download Presentation

Universal Gravitation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Universal Gravitation Chapter 8

  2. 8.1 Motion in the Heavens and on Earth • Stars - regular path • Planets - wanderers, complicated path • Comets - more erratic path Galileo, Kepler, & Newton provided insight into how objects move.

  3. Tycho Brahe observed eclipse of sun & vowed to become astronomer. • Persuaded King Frederick I of Denmark to give him the island of Hven as observatory. • Worked for 20 years there.

  4. In 1597, became astronomer to Emperor Rudolph of Bohemia where his assistant was Kepler. • Brahe - earth centered • Kepler - sun centered • Analyzed Brahe’s data and formulated three laws of motion.

  5. Three Laws • 1. Path of planets are ellipses with the sun at the center. • 2. An imaginary line from the sun to planet sweeps out equal areas in equal time intervals. Move fastest when closest to the sun. • 3. (Ta/Tb)2 = (ra/rb)3

  6. Table 8-1 Planetary Data p 178 • Newton used mathematical properties to prove Kepler’s first law. • F  1/d2 • F = G (m1m2/d2) • Because force depends on 1/d2, its called the inverse square law.

  7. Fig 8-3 p 182 Gravitational Forces

  8. mp = mass of planet • ms = mass of sun • r = radius of planet’s orbit • T= time for one revolution • G = universal gravitation constant • F = ma F = mpac

  9. G(ms mp/ r2) = mp(42r/T2) • T2 = (42/Gms)r3 which is Kepler’s third law • Cavendish tested law of universal gravitation between small masses on Earth.

  10. Able to measure the constant G in Newton’s Law of Universal Gravitation. • Me = 5.98E24 kg

  11. References • http://www.walter-fendt.de/ph11e/keplerlaw1.htm • http://www.walter-fendt.de/ph11e/keplerlaw2.htm • http://www.physicsclassroom.com/mmedia/circmot/ksl.html • http://www.pbs.org/wgbh/nova/einstein/relativity/ • http://www.spaceref.com/tools/vi.html?id=139&cat=blackholes&imgs=movie • http://www.physicsclassroom.com/mmedia/specrel/lc.html

More Related