An explanation on how satellites are put into orbit.

Explain how an object is put into orbit about the Earth (to become a satellite)? Include the relationship between gravity and velocity.

Understanding planet retrograde motion.

How can planet retrograde motion be explained by the Earth center hypothesis? By the Sun-center hypothesis?

Calculating the gravitational ratio between the Sun and the Earth.

The Sun does not pull you off the Earth. The sun is approximately 10^6 times as massive as earth, but at the Earth's surface, you are about 2.5 x 10^4 times as far from the center of the sun as you are from the Earth's center. By what factor is the Earth's gravitational pull on you stronger than the sun's?

"Geosynchronous" orbit problem

"Geosynchronous" satellites orbit at the same rate that the earth spins. A satellite is in "geostationary" orbit when it always stays above the same location on the earths surface. For geostationary orbits: Can this location be anywhere on earth? If not, where can it be? Is any altitude possible for these satellites? why? Are either of the above restrictions affected by the satellites sixe? why? Are either of the above restrictions affected by the satellites mass? why? Why do we use geostationary orbits? (Kepler's laws can help with these questions)

How rocks can be determined by radioactivity.

Explain how the age of rocks can be determined by radioactivity. Give an example.