(a). Modulus of elasticity and modulus of rigidity are important parameters to measure mechanical properties of materials. With the aid of drawings, explain these parameters and give some examples of how they vary for different materials.

(b). In a tensile test conducted on a sample of the material, a full range of stress-strain curve can be measured until the sample breaks, describe such a curve and explain properly for key terminologies such as elastic range, plastic range, yield stress, ultimate tensile stress etc.

 (c). A circular metal column is to support a load of 860 Tonnes and it must not compress more than 0.2 mm. The modulus of elasticity is 220 Gpa, the column is 2.1 m long. Calculate the cross section area and the diameter.

(d). A punch must cut a hole 46 mm diameter in a sheet of steel 2.8 mm thick. The ultimate shear stress is 60 Mpa. Determine the minimum force that is required to cut the hole.