Earth's magnetic field is evidence for which of its following features? A. Solid iron inner core surrounded by fluid iron
Crust made up of iron,

B. oxygen, silicon, and magnesium

C. Extremely high temperatures in the mantle

D. Variable density and composition based on depth

Total solidification times of three casting geometries are to be compared: a sphere, a cylinder, in which the length-to-diameter ration - 1.0, and a cube. volume = 1000 cm^3 for all three shhapes, and the same casting alloy is used. a) determine the solidification times of each geometry b) based on the results of part (a), which geometric element would make the best riser? c) if the mold constant = 3.5 min/cm^2 in chvorinov's rule, compute the total solidification time for each casting.