일반물리학 1 — Gravitation: Problem 68

68 A satellite orbits a planet of unknown mass in a circle of radius \(3.0 \times 10^7 \text{ m}\). The magnitude of the gravitational force on the satellite from the planet is \(F = 80 \text{ N}\). (a) What is the kinetic energy of the satellite in this orbit? (b) What would \(F\) be if the orbit radius were increased to \(4.0 \times 10^7 \text{ m}\)?