Equilibrium of force

You know (c1):

Centrifugal force = Gravitation

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Synonyms:
Rp = Orbit of the planet,
Vp = Orbit speed of the planet,
Mp = Mass of the planet,
Ms = Mass of Sun,
and the gravitational contstant:

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Multiplying (c1) by Rp2 / Mp you get: (c2):

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This equation can be used in case of Earth as well as in case of Venus and you find second Kepler’s law (c3):

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where
Vv = Orbit speed of Venus,
Ve = Orbit speed of Earth,
Rv = Orbit of Venus,
Re = Orbit of Earth.

If you assume, that orbit of Earth is to be familiar with Re = 1,496*1011 m (astronomical unit AU), you compute the orbit speed of Earth by using time of circulation Te like 1 Jahr = 31 557 600 seconds.

Taking (c4):