Hi. This question is mostly done by a figure; we have a loaded truck of weight W being pulled by a truck with a force F. The CM point on the figure ndicates the location of the center of mass of the trailer and its load. Suppose the trailer accelerates forward (a>0) or backwards (a<0). What is the vertical component F_y of the force F on the trailer? For the forces in the X and Y I have: [tex]\sum F_x = ma[/tex] (since there is some acceleration) [tex]\sum F_y = n + F_y - W = 0[/tex] Now, I suppose, I'm to write an equation for the torque, but this one isn't that easy - where do i put the origin? thank you.