Partial preview of the text
Download Orbital Motion: Newton - Lecture Notes | ASTRO 342 and more Study notes Astronomy in PDF only on Docsity!
Roce ene Re sate ts aise athe US te PSN a SE aE Ue IO wate Labs elebere Moan the nclatad late tats te We re iN Fat Nha a rm etd a te et Nt ane Lh Fae ESCM Peat BA SDSS UA IES ts O15 de Zane Ue RRR by UTA NE Orbital Motion: Newton (/643- (727 ) Kepler's laws are empirical relations. They solved the problem of planetary motion, but they suggested no generalizations beyond the immediate problem, and opened the question - why should planetary orbits be elliptical? Newton: proceeded with a first principles approach in deriving his laws of mechanics and his Universal Law of Gravitation. Mechanics: Newton's three laws determine the mo‘ions of point particles (in “absolute” space and time) subject to external forces. Newton's Laws (Principia) 1. Every body continues in a state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it. t ( life friction ) 2. ‘The change of motion is proportional to the force impressed; and is made in the direction of the straight line in which that force is impressed. a=, Fame 3. To every action there is always an equal and opposite reaction: or, the mutual actions of two bodies upon each other are always equal, and act ia opposite directions. ‘tf = sf /1,4 = “Ma 42 
