February 20, 2008

February 20, 2008 - February 20, 2008 WRITTEN HW DUE MONDAY...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
February 20, 2008 WRITTEN HW DUE MONDAY LUNAR ECLIPSE TONIGHT FROM 6:45 TO 10:09 How many planets have rings? o 4, Jupiter Neptune Saturn and Uranus o The gas giants have rings Rings are very different than moons o Not all the planets even have moons o Earth Mares Jupiter Saturn Uranus and Neptune have moons Suppose earth were moved to one-third of its current distance from the sun. What would happen to the gravitational force between Earth and Sun. o Mathematical approach: F g = G [(M 1 M 2 )/ d^2] F new /F old = {G [(M S M E )/ ((1/3d)^2)]}/{ G [(M S M E )/ d^2]} = 1/(1/9) = 9 (everything cancels out) Multiply both sides by F old => F new = 9F old F new is greater by 9 o Logical Way F = (GM 1 M 2 )/(d^2) d decreases by 3 d^2 decreases by 9 F increases by 9 Newton’s version of Kepler’s third law o Orbital period = totally distance/speed o Circular orbit P = 2pia/V circ r = a for circular orbits p^2 = (2pir)^2/(V circ )^2 p^2 = (4pi^2a^2)/(GM/a) p^2 = [4pi^2/GM]a^3 (something)a^2/(something/a) Bring the a up to the top
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/07/2008 for the course ASTR 1110 taught by Professor Hornstein during the Spring '08 term at Colorado.

Page1 / 2

February 20, 2008 - February 20, 2008 WRITTEN HW DUE MONDAY...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online