We all know that the Centrifugal force is not a real force.However,we can use it mathematically. This Wikipedia Article on Centrifugal force States that: But, According to Newton's first law,objects tend to move in a straight line or stay at rest at a constant velocity unless no external force is acted. The Centrifugal force should act on the velocity direction.If so,Why does the wikipedia article says this. Moreover,There have been many ideas of artificial Gravity using centrifugal force.(So,in favor of wikipedia article) Whatever the Wikipedia,My question is why does not the force act at velocity direction?