8. Centripetal Forces & Gravitation

Three satellites, A, B, and C, orbit Earth in circular orbits at different altitudes: Satellite A is closest to Earth, Satellite B is at a medium altitude, and Satellite C is farthest from Earth. Rank the satellites in order of increasing orbital period.

Which of the following would cause the greatest increase in the acceleration of a satellite in circular orbit around Earth ($a=\frac{v}{r^2}$ or $a=\frac{\mathrm{GM}}{r^2}$)?

Why must a geostationary satellite orbit Earth in exactly $1$ sidereal day?

Which of the following orbits has the largest semimajor axis?