Question

Describe Kepler’s 3 laws and how they differ from the earlier proposed theories of planetary motion

Answer 1

1st : all planets in orbit follow an elliptical path (not circular) and the sun (or other object orbiting around) at one of the focal points of the elipse

2nd : as the planet orbits the sun, it sweeps equal areas of the elipse in a given time, therefore it is faster when closer to orbit.

3rd: basically this is a formula, the square of a planets period is proportional to the cube of the distance between the planet and sun.

remember these apply for all cases where an object orbits another with significantly larger mass.

Answer 2

In the early 1600s, Johannes Kepler proposed three laws of planetary motion. Kepler was able to summarize the carefully collected data of his mentor - Tycho Brahe - with three statements that described the motion of planets in a sun-centered solar system. Kepler's efforts to explain the underlying reasons for such motions are no longer accepted; nonetheless, the actual laws themselves are still considered an accurate description of the motion of any planet and any satellite.

Kepler's three laws of planetary motion can be described as follows:

The path of the planets about the sun is elliptical in shape, with the center of the sun being located at one focus. (The Law of Ellipses)
An imaginary line drawn from the center of the sun to the center of the planet will sweep out equal areas in equal intervals of time. (The Law of Equal Areas)
The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun. (The Law of Harmonies)