Kepler's second law (area law): The straight line from the sun to the planet sweeps the same area at the same time. ?
Expressed by the formula: SAB=SCD=SEK?
Simple proof: With the sun as the rotation axis, the torque to the planet is zero due to the tangential component of gravity, so the angular momentum of the planet is a constant, which is equal to the mass of the planet multiplied by the speed and the distance from the sun, that is, L=mvr, where M is also a constant, so vr is a constant. In a short time △t, the area swept by R is about equal to vr△t/2, that is, only VR △ T/kl.
Kepler's third law (periodic law): The ratio of the cube of the semi-long axis of all planetary orbits to the square of period of revolution is equal. ?
Expressed by the formula: r 3/t 2 = k?
Where r is the semi-major axis of the planetary orbit, t is the planetary period of revolution, and k = GM/4π 2 = constant.
Kepler's three laws about the laws of planetary motion are:
All the planets revolve around the sun in different elliptical orbits, and the sun is located at a focus of these ellipses.
② For each planet, the connecting line between the planet and the sun sweeps the same area in any equal time (the "area velocity" is constant).
③ The ratio of the cube of the semi-long axis of elliptical orbits of all planets to the square of period of revolution is equal.
Also known as "Kepler's three laws" and "laws of planetary motion", it refers to the laws that planets follow when they revolve around the sun in space. Because the German astronomer Kepler proposed it as early as 1609 ~ 16 19 based on the observation data and catalogue of Danish astronomer tycho brahe and others, the laws of planetary motion refer to Kepler's three laws. ?
The specific content of Kepler's second law Kepler published two laws about planetary motion in 1609:?
Kepler's first law (orbital law): All planets orbit the sun in an ellipse, and the sun is at a focal point of the ellipse. ?
Kepler's second law (area law): For any planet, its line with the sun sweeps the same area at the same time. ?
Expressed by the formula: SAB=SCD=SEK?
Simple proof: With the sun as the rotation axis, the torque to the planet is zero due to the tangential component of gravity, so the angular momentum of the planet is a constant, which is equal to the mass of the planet multiplied by the speed and the distance from the sun, that is, L=mvr, where M is also a constant, so vr is a constant. In a short time △t, the area swept by R is about equal to vr△t/2, that is, only VR △ T/kl.
1609, these two laws were published in his New Astronomy. ?
16 19 Kepler discovers the third law:?
Kepler's third law (periodic law): The ratio of the cube of the semi-long axis of all planetary orbits to the square of period of revolution is equal.
Expressed by the formula: r 3/t 2 = k
Where r is the semi-major axis of the planetary orbit, t is the planetary period of revolution, and k = GM/4π 2 = constant.
Finally, Kepler's law is proved and deduced by scientists, and we can pull it out as long as we know how to use it.
If you are particularly interested, you can deduce ~ ~ ~ yourself after you engage in this field in the future.
Come on! ! !