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Satellite Communicationsever increasing widespread Part 15

Tham khảo tài liệu 'satellite communicationsever increasing widespread part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Satellite Motion 481 b The Second Kepler s Law of Planetary Motion This law can be expressed as follows The radius vector drawn from the Sun to a planet covers equal areas in equal times. The Law of equal areas Mathematically this law can be expressed with the equation d I r 26 0 dt V 2 I 14 where 6 is angular velocity of true anomaly 1 .2 r 6 is the areal velocity that the radius vector r drawn from the Sun to the planet sweeps in one second Fig. 12 . From this law it follows that the speed at which any planet moves through space is continuously by changing. A planet moves most quickly when it s closer to the Sun and more slowly when it is further from the Sun. c The Third Kepler s Law of Planetary Motion This law can be expressed as follows The squares of the periodic times of the planets are proportional to the cubes of the semi-major axes of their orbits. The harmonic law This law is giving the relationship between the distance of planets from the Sun and their orbital periods. Mathematically and symbolically it s possible to express as follows P2 a a3 where P is the orbital period of circulate planet around the Sun and a is the semi-major axis of this orbit. Because this proportionality is the same for any planet which rotates around the Sun it s possible to write the next equation P2 _ P2 P2 a3 planetl planet 2 namely planet 1 _ planet 1 15 3 3. J P2 . . a3 aplanet1 aplanet 2 planet 2 planet 2 3. The Physical Laws of Motions Sir Isaac Newton s formulated three fundamental laws of the classical mechanics and the law of gravitation in his great work Philosophies Naturalis Principia Mathematica published on July 5 1687. Before Isaac Newton the great contribution to the advance of mechanic was given by Galileo Kepler and Huygens. 3.1 The First Law of Motion - Law of Inertia This law can be expressed as follows 482 Satellite Communications Everybody persists in its state of being at rest or moving uniformly straightforward except insofar as it is compelled to .