Homework:

Communications satellites should stay in or close to the same place of the sky all the time. Otherwise one would have to constantly move the satellite dish to get good reception. Such orbits are called geo-stationary or geo-synchronous. Assume a circular geo-stationary orbit in the equatorial plane of the earth.

1. Find the period and the radius of this orbit.
2. Assume that the satellite is at a fixed longitude of $118^{\circ}$ west (same as LA) in what direction do you have to point your dish if you live in LA ($32^{\circ}$ north).
3. For the same satellite what direction do you have to point your dish if you live in Las Vegas ($33^{\circ}$ north and $115^{\circ}$ west.)?