These laws describe the motion of any two bodies in orbit around each other. The masses of the two bodies can be nearly equal, e.g. CharonPluto (~1:10), in a small proportion, e.g. MoonEarth (~1:100), or in a great proportion, e.g. MercurySun (~1:10,000,000).In all cases, rotation is about the barycenter of the two bodies, with neither one having their center of mass exactly at one focus of an ellipse. However, both orbits are ellipses with one focus at the barycenter. When the ratio of masses is large, e.g., with planets orbiting the Sun, the barycenter is deep within the larger object, close to its center of mass. In this case it requires sophisticated precision measurements to detect the separation of the barycenter from the center of mass of the larger object.Kepler's laws are concerned with the motion of the planets around the sun. Newton's laws of motion in general are concerned with the motion of objects subject to impressed forces. Newton's law of universal gravitation describes how masses attract each other through the force of gravity. Using the law of gravitation to determine the impressed forces in Newton's laws of motion enables the calculation of planetary orbits,
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.