Where does centrifugal force come from in satellite motion?
There is no such thing as “centrifugal” force. The force you are (and did, once, in the additional details field) referring to is “centripetal” force. Centripetal force is responsible for an object’s circular motion. At any instant in time, the velocity of an object is pointed tangent to the circle even though the object keeps moving around the circle. In order for this to occur, the velocity vector must constant be changing, and thus an acceleration is needed (even though the object’s speed might be constant). The direction of the force needed is inward toward the axis of rotation. When talking about a satellite in a circular orbit around the Earth, gravity is providing its centripetal force. Gravity exerts a force which pulls the satellite inward towards the axis of rotation (towards the center of the Earth’s mass). When the object is in equilibrium, the gravitational force equals the centripetal force. F_g = F_c G * M * m / r^2 = m * v^2 / r Masses (m) cancel and we are left with th
