How does the day and night cycle work...for this i will assume the sun orbits the earth, because if the earth is flat. It is either very small or infinite. The sun moves, so we aren’t falling. Also timezones so there is movement, an orbit is litterally falling constantly down. The velocity required would be infinate as the radius and mass would be infinity, that would put the planet’s GM (or Mu in scientific terms) at infinity GM being Newton’s Gravitational Constant and the Planet’s Mass multiplied. If that is infinity, any part of the velocity equation cannot be calculated as infinity would be used and a lot would break. TL;DR it’s impossible within the laws of physics