First off, this isnt a homework question, its a variation on a problem I have in one of my books. Ive drawn a diagram below In the diagram, there are to objects of mass m1 and m2, which are connected by some rope, which is fed through that eyelet on the rod, which is perpendicular to the ceiling. Im wondering what the force is pulling m1 to the right? From my understanding, there is a force acting downwards on the rod with the eyelet, which is from the weight of m2. Now I know that this force will cause m1 to slide to the right, when it overcomes the force of friction. But I cant figure out how to explain the force pulling m1 to the right on paper. If the rod with the eyelet was at an angle, then I could use the triangle law, but seeing as its perpendicular, there is no triangle formed. So what is indeed, pulling m1 to the right?