AST101H1 Lecture Notes - Lecture 8: Tidal Force, Synchronous Orbit, Tidal Locking

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Eryan Apsnler, Michael Reid

Document Summary

Gravity and orbits (cont. ) (continued from lecture 7 notes) Isaac newton: took kepler"s descriptive laws and explained why they worked. Newton realized that all motion could be described through three simple laws. 1st law: objects move with constant speed and direction unless acted on by an external force. 2nd law: force = mass x acceleration. Weight is the amount of gravitational force one is experiencing. 3rd law: if one body exerts a force unto another, whatever body the force is applied upon will exert a force of equal strength but in an opposite direction. Kepler"s laws tell only the possible shapes orbits can manifest, but not why things orbit to begin with. Newton"s law of gravity: fgravity = gmm/r^2. Tidal force = difference in the force of gravity felt between two points due to distance. Tidal gravity of the moon (and to a lesser extent, the sun), enables tides to manifest on earth.