After completer chapitre 5, you try to solve these problems:

1. Find a real physical example of a mechanical structure or machine that has tensile stress present.
   (a) Make a clear labeled drawing of the situation.
   (b) Estimate the dimensions of the structure or machine and the magnitudes and directions of the forces that act on it. Show these on the drawing. Briefly explain why you estimate the dimensions and forces to have the numerical values that you assigned.
   (c) Calculate the magnitude of the stress.

2. A 1 Mg container hangs from a 15 mm diameter steel cable. What is the stress in the cable?

3. Determine the elastic modulus and the yield strength for the material havingthe stress–strain curve shown in Figure 1. Use the 0.2% offset method.

4. Recent technological advances have allowed for the production of graphene, which is a sheet of carbon atoms one atom thick, densely packed into a honeycomb structure. This material has excellent electrical, thermal, and optical properties, making it an ideal candidate for the design of electronic components. These characteristics are further complemented by graphene’s ability to kill bacteria and by its breaking strength, which initial tests demonstrate is 200 times greater than steel. Research this material and prepare an approximately 250-word report on the current engineering applications for graphene. Cite at least three references for your information.

5. Structural steel and stainless steel are both primarily made of iron. Why doesn’t stainless steel rust? Research the issue and prepare an approximately 250-word report describing the reason. Cite at least three references for your information.

 Figure 1: stress–strain curve