I don't have a specific homework assignment, but rather my problem is with the general concept. I don't understand the forces acting in uniform circular motion. As I understand it, the force is directed inward, and there is no other force in the same dimension (in an idealized model). But in my mind, that would mean you would be flung towards the center, or at least slowly move towards the center in a spiral. If I imagine a Gravitron that moves really fast and causes you to be pushed back against the wall, there should be an acceleration towards the center, but also a tangential force "trying to leave" the circle in a straight line, in the direction of the velocity vector. But in the free-body diagram in my book, there is only a centripetal force in the direction of the radius (the normal force in this case). I can understand that perhaps it doesn't show because it is not a force acted on me, but by me. But I still feel like there should be some force that causes the tangential velocity in the first place, and that causes me to speed up enough to "lift" from the floor. After all, both me and the Gravitron would be standing still to begin with. Please, I am not questioning the validity of the idea that there is only a force inward. I just need help understanding in a way that helps change my intuition.