Question

What is the specific gravity means and how does specific gravity related to solid materials,

Answer 1

Specific gravity is the mass or density of a substance expressed as a ratio of the same volume of that substance in a standard reference substance. For solids, the reference substance is usually water. For example, if solid substance Z has a specific density of 1.5, that means that solid substance Z weighs 1.5 times as much as the standard substance (water).