Does the centrifugal force of the Earths rotation affect the Earth itself?
[Optional] You are sitting on a rotating platform, right on the middle. You want one of the people sitting nearer to the edge of the platform to join you at the middle, so you extend your hand and pull that person in, against the centrifugal force. What do you think: do you need energy to overcome the centrifugal force? Does your arm perform work? If you guessed that you did need energy, you are right. There exists an interesting application. You are probably aware children can “pump up” a swing and keep it going; you may even have done so yourself. How is it done? The process is best seen in swings on which you stand rather than sit. The centrifugal force on the swing varies: it is greatest at the bottom of the swing, where motion is fastest, but zero when the swing briefly stops at the end points. What you do is, near the end points you lower your body, then near the bottom of the swing you stand up straight again. By standing up, you overcome the centrifugal force, which is directed
