B/ Choose correct answer from the following (choose 5 only): 1. The iron ore mostly used for the production of pig Iron is: b) Hematite a) Cuprite c) Bauxite d) Bornite 2. In TIG arc welding, the welding zone is shielded by an atmosphere of: a. Helium b) Hydrogen c) Nitrogen 3. A moving mandrel is used in: a) wire drawing b) tube drawing c) metal cutting d) Acetylene d) forging

QUESTION 3 A Type I offshore life jacket (i.e. personal flotation device) is the type worn by commercial fishermen - it is designed for extended survival in rough, open seawater. Consider such a life jacket that uses an impermeable foam material with a density of 32 kg/m³ - the other parts of the life jacket (straps, fasteners, etc) weigh 0.6 kg and are of negligible volume to the design. a) Draw a free body force diagram for the life jacket. b) Determine the minimum volume of foam material (in L) that is needed for the life jacket in order to provide a minimum 98 N net upward force when it is fully submerged in seawater (as required by US Coast Guard regulations).