AS101 Lecture Notes - Ellipse, Weightlessness, Inverse-Square Law
Document Summary
According to the law of gravitation, force of gravity between the earth and an object of mass m: f=gm mearth d2. According to newton"s second law, this force can also be written as: f=ma. Equating the two, we see that the acceleration does not depend on the objects mass: g= gmearth d2. In physics mass and weight are related but are not the same thing. Mass is the amount of matter in an object. Mass in an intrinsic property of an object. Mass is the same no matter what forces are acting on an object. Weight is the force of gravity exerted on an object. Weight is directly proportional to the mass. Example: doubling your mass doubles your weight. Weight varies from planet to planet since the acceleration due to gravity varies. An object orbiting earth is actually falling (being accelerated) towards earth"s center: an object in a stable orbit continuously misses the earth because of its orbital velocity.
