I am a bit confused about such forces that act in a string or a spring. I am unable to guess their direction. Therefor I prepared myslf some examples through which i can understan the concpt of these forces. In diag1 A force F is applied at end C. What will b the tensions at points A,B(mid point),C. Find their directions and their magnitues. (if the string has no mass) I can guess about tension at point A. Its going to pull the block of mass m. Therefore, tension will act away in the rightward direction. Am I right? What about the other points?