ASTRO 142 Lecture Notes - Lecture 3: Inverse-Square Law, Momentum, Ellipse
Document Summary
Newton informed halley about the orbit as an ellipse. First law of motion focuses on how objects move if left on their own. Scientists at the time knew aristoleian mechanics were incompatible. Newton"s first law: uniform motion and law of inertia: clarified force as something that causes a body to change its state. A change in velocity means a change with respect to time of speed or direction or both. Newton"s second law: f=ma: defined mass. Property by which an object resists a change in its state of motion. Greater a mass, the larger force required to produce a certain acceleration: linear momentum. Vector consists of a magnitude and a direction and can be represented as an arrow. Without the force of gravity, planets would not orbit but would travel forever through space in a straight line. Newton"s third law: every reaction, there is an equal and opposite reaction.
