1. The problem statement, all variables and given/known data A cable is spanned between two points at the left touching the ground and at the right smoothly spanned over a large roller. Assume that there's no friction present. The tension left at the bottom is H and the tension T at the top is such that T>H. The cable has a weight per unit length q and is spanned over an height h and is in static equibrilium. Prove that: T = H +q*h http://img220.imageshack.us/img220/537/96775335.png [Broken] 2. Relevant equations 3. The attempt at a solution I thought that the roller would give reaction forces perpendicular to the cable but other students told me that it works like a pulley and since there's the assumption that there's no friction I can disregard these forces, right? But I still don't know how to prove that formula.