6. (20 pts) Pure copper is poured into a sand mold. The metal level in the pouring basin is 250 mm above the metal level in the mold, and the runner is circular with a 10-mm diameter. What are the velocity and rate of the flow of the metal into the mold? Is the flow turbulent or laminar? Density (p) 2700 kg/m, viscosity (n)= 0.0015 Ns/m And if Reynold number Re flow is turbulent vDp 71 is less than 20,000 then the flow is laminar otherwise 7. (7.5 pts) Describe the investment shell-casting steps and explain the differences between ceramic shell casting. 8. (5 pts) if large scale metal with accurate content is desired to be produced by casting which type furnace must be used. Explain how the problems are solved by your suggestion.