AST101H1 Chapter Notes - Chapter 4: Conservation Law, Tidal Force, Synchronous Orbit

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

Document Summary

Isaac newton: explained why kepler"s laws worked (chapter 4) First law: objects move with constant speed and direction unless acted on by an external force. Third law: if one body exerts a force on another, the other body will exert a force of equal strength but opposite direction. Explains why things orbit -> keeps moon in orbit around the earth. Angular momentum: any object spinning along a curved path e. g. earth due to its rotation. Weight: force that a scale measures (depends on mass and forces acting on your mass) Possible orbital shapes: ellipses (bound orbits), parabolas or hyperbolas (unbound orbits but still obey kepler"s second law) Conservation of momentum: if there is no external forces, total momentum will not change. Conservation of angular momentum: if there is no external torque, total angular momentum will not change (angular momentum = mvr; bigger radius, lower velocity) Rotational angular momentum (rotate on its axis)