... Kepler's 3rd Law . 21a.Applying 3rd Law . ... Besides the Moon, Earth now has many artificial satellites, put up by us earthlings for a variety of purposes. ... where for a satellite orbitingEarth at distance of one Earth radius R E , the constant k equals k=gR E 2 . ... The velocity for a circular Earthorbit at any other distance r is similarly calculated, but one must take into account that the force of gravity is weaker at greater distances, by a factor (R E / r) 2 . ...
Besides the Moon, Earth now has many artificial satellites, put up by us earthlings for a variety of purposes. ... In principle, a satellite could then orbit just above its surface. ... Dividing both sides by m shows that the mass of the satellite does not matter, and leaves . ... Any slower and it loses altitude and hits the Earth ("2"), any faster and it rises to greater distance ("3"). ... This is Kepler's 3rd law , for the special case of circular orbits around Earth. ...
Phoebe . Saturn IX . Phoebe [FEE-bee] is the last of the known satellites of Saturn, at a distance of 12.952 million kilometers (8 million miles). Phoebe orbits Saturn in a retrograde direction (opposite to the direction of the other satellites' orbits) in a plane much closer to the ecliptic than to Saturn's equatorial plane. ... Scientists believe that Phoebe may be a captured asteroid with a composition unmodified since the time it was formed in the outer Solar System . ...