1. The problem statement, all variables and given/known data What is the relationship between the weight of the hanging washers and the force acting on the stopper by the string? Here is the diagram provided by the book: http://www.goodreads.com/photo/user/5034346-kylaia-formerly-known-as-klymene?photo=454140 It also says to simply assume L=R 2. Relevant equations ƩF=ma, where the sum of the forces equals mass times acceleration. ƩF=(mv2)/r, where the sum of the forces on an object in rotation equals mass times velocity squared, all divided by the radius W=mg, where the force of the weight equals mass times the acceleration due to gravity (9.8) 3. The attempt at a solution The only force acting on the stopper, since it is in rotation, is the tension of the string. ƩFstopper=(mstoppervstopper)/r There is tension and weight acting on the washers. ƩFwashers=Twashers-Wwashers=0 Therefore, Twashers=Wwashers=mwashers*9.8 I'm guessing that somehow, the system has to be in equilibrium, because that's the only way anything could be put in a relationship. But I don't see how it could possibly be in equilibrium. And I don't understand how to relate the forces on the washers to the force acting on the stopper. It's all purely theoretical, so there are no given numbers.