ASTR 001 Lecture Notes - Lecture 6: Inverse-Square Law

• School: Pasadena City College
• Department: Astronomy
• Course: ASTR 001
• Professor: Hartman

Document Summary

Velocity: the speed and direction of an object"s motion. A change in velocity is called acceleration. Acceleration measures how quickly a change in motion takes place. If you change speed or direction, the object will accelerate. Newton"s law of motion: for every force, there is an equal and opposite force. The two forces have the same size. Kepler"s laws of orbits and newton"s laws of motion and gravity are only the beginning. Gravity is very important for shaping objects and orbits. Two high tides on earth a day. Two low tides a day on earth. Gravity is an attractive force between any two objects with mass, acting along the line between them. The gravitational force results in an acceleration. All objects on earth fall with the same acceleration, known as g. The m terms are the two masses. The force is proportional to the mass of each object. The distance between the objects is r.