• Often people, when summing the forces in say the X-dirrection, will ignore any force that is not exactly along the X-dirrection. When summing in a particular dirrection we have to remember about the componets of a force. So even if a force isn't exactly in the X-dirrection, as long as its not perfectly in the Y-dirrection, the force will have some componet in the X-dirrection that we will need to sum as shown in the example FBD below.