Let's begin by describing the engineering problem that you'll be solving in this lesson.
Your company has acquired some scrap cylindrical steel rods. These rods are currently stacked in a bin. The radii of all of the rods are known (their lengths are irrelevant). In addition, the X-Y coordinate positions of the rods at the bottom of the bin are also known. (For this problem, the X-Y coordinate origin is at the bottom left-hand corner of the bin.)
Your task is to determine the X-Y coordinate positions of the centers of all the rods in the bin. Knowing the positions of all the rods would allow you to compute the forces on the floor and walls of the bin, so that you could tell if the bin were strong enough to hold the rods. You won't be asked to compute the forces, though--just computing the positions is enough work for today!