Calculate the wire pressure for a round copper bar with an original cross-sectional area of 12.56 mm2 to a 30% reduction of area, given that the included die angle is 300 with a coefficient of friction (μ) of 0.08 and the yield stress for copper is 350 mpa.

Analyze the factors that influence the choice between the following pairs of processes to make the products indicated: i) sand casting versus die casting of an electric-motor housing ii) thread rolling versus machining of a bolt for high-strength application. (co3/c5)