Hi. Could you please help me with the following problem. There is a ball in a centrifuge, which is moving with the velocity v. Assuming speed of the centrifuge is high enough so that the ball is moving inside it. How to calculate the normal force, acting on a ball from the centrifuge's walls? We should take friction into account. But how can we do it? What kind of friction are we dealing with? Can we tell from the problem whether there is any slipping? Or not? What should we know to be able to solve the problem? Thank you in advance.