Now that the idea of a force is well-pounded into your head, we can actually use this seemingly bland knowledge to perform stupendous, mind-boggling, attention-catching feats.

Engineers (and now you) often make simple, though still perfectly good, sketches called Free Body Diagrams to show the position of all the forces acting on an object. They get their name from the fact that they have been cut free from their surroundings, allowing a close examination of the forces acting on them. In our example at right, we've broken down the forces on a hanging obelisk (don't ask for an explanation, for the idea or the picture) to three simple ones: gravity pulling it down and the two ropes keeping it up. However, all forces are represented the same in the free body diagram. By simplifying the forces like this, it becomes possible to solve a system using math, which we'll explore later in Calculating Equilibrium.

Ok, now we can figure out how strong our two ropes need to be (this is our wonderful ability that was mentioned before, hope you're not disappointed). To do this, we don't think about how force is transfered around, or anything like that. Instead, we make one assumption: our obelisk is in equilibrium, which means that it isn't moving in any direction: acceleration is zero. Therefore, the sum of forces in each direction has to be zero, by Newton's Second Law. All the down forces are going to have to equal all the up forces, and all the left-pointing forces are going to have to equal all the right-pointing forces (there's more, but we'll get to that later in Moments, Not What You Thought They Were). One simple way to do this is to break a force into its vertical and horizontal components (remember those from The Parallelogram Law?). So, the sum of the vertical components of Forces F2 and F3 are going to have to equal Force F1 (up forces equal down forces), and the horizontal component of F2 is going to have to equal the horizontal component of F3 (left forces equal right forces).

You may be telling yourself that if this gets any more stupendous and mind-boggling you might have to drop your computer from a two-story building in utter frustration and anger, but hold on there.....there is a light at the end of the tunnel.It could be our next topic, but I'm not sure about that.

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