I'm trying to create a simulation of some frameworks. For my situation, these are light (I'm ignoring their weight) rods connected by joints. Currently, the joints do not hinge or otherwise move and can have a weight, effectively a force applied to the point. Oh, and I'm also ignoring air resistance. I thought I knew enough mechanics to work this out; however, I'm having some trouble. Say we simply have 2 joints with a rod between them, neither joint has the same weight and this system is currently falling. At first I tried calculating the tension each weight would put on the rod and then exerting the difference between the tensions onto the point that caused the least tension. Needless to say, this didn't work. Now, I'm attempting to use moments about the centre of mass of the rod, ie the centre of the rod. However, I don't understand how to calculate the acceleration caused, in x and y components, by the moments. Any help would be great, thanks a lot!