General Instructions. In problems requiring the specification of sizes for steel cable,...

General Instructions. In problems requiring the specification of sizes for steel cable, bar, or pipe, selections should be made from Tables 3.1–3.3. In all problems, write a brief technical report following the guidelines of Appendix A, where you summarize all pertinent information in a well-organized fashion. It should be written using proper, simple English that is easy for another engineer to read. Where appropriate, sketches, along with critical dimensions, should be included. Discuss the objectives and constraints considered in your design, the process used to arrive at your final design, safety issues if appropriate, and so on. The main discussion should be typed, and figures, if needed, can be computer-drawn or neatly hand-drawn. Include a neat copy of all supporting calculations in an appendix that you can refer to in the main discussion of your report. A length of a few pages, plus appendix, should be sufficient.

You are working for the Peace Corps in an impoverished country that needs your help. Your job is to design a simple but accurate scale for weighing bulk materials such as food and construction materials. A possible idea consists of a loading platform D that is supported by cable AB, where end A is attached to a large tree limb. After loading platform D, weight W₃ is applied, which causes point B to move horizontally by a small distance i that is to be measured with a yardstick.