(a) Show that the porosity of a cubic packing of spherical grains of any diameter d is 47.6%. (b) Insert a spherical grain of diameter d in the void space between the grains in (a) and recalculate the porosity. D n D H. diagonal from one corner to another in a different plane. not perpendicular h. diagonal from one comer to another in 1 the same plane (c) Insert a spherical grain of diameter d3 in the void space between the grains in (a) and (b) and recalculate the porosity. (d) Repeat the process above for n diameters and plot porosity versus the diameter of the grains.