Hello everybody! First of all,I would like to apologize for my English because I'm not a native speaker. I'm 16 and I have a pretty good knowledge on physics but I need help with solving certain type of problems. In my country we now have a summer vacation so I decided to look for a forum where I could post my problems and get help with their solutions. Also, I would like to help others. Here is my first problem, in field of mechanics: "Over a fixed pulley with a very small radius and negligable mass passes a chain of mass m and length l. The chain begins to slide. Let x be the distance between its ends. find in term of x: a)the acceleration of the chain and b) the force that the chain exerts on the pulley". I've managed to solve point a: a=g*x/l. But i'm struggling on point b. My first thought was that the force exerted by the chain on the pulley must be equal to the weight of the chain. But this can't be true, because as the chain slides down, the forces exerted by each piece of chain (the one on the left ogfthe pulley and the one on its right) don't remain the same so that must change something on the resultant force acting on the pulley, I think....Please, help solve this problem! I'll wait for your thoughts, suggestions, ideas. And if you don't understand something I wrote here, please tell me so I can reformulate. As I said, I am not a native speaker. Thanks a lot!