What describes specific weight?

Specific weight is defined as the weight of a substance per unit volume. It is a property that relates the heaviness of a material to the space it occupies, which is fundamental in fields like engineering and fluid mechanics. In simple terms, when you take a material and measure how much it weighs for every cubic meter (or other volume units), you get its specific weight.

This concept is especially important when comparing different materials or when determining how substances behave when subjected to forces such as buoyancy. It plays a crucial role in calculating pressures in fluids and understanding how materials may float or sink.

The other options relate to different concepts. Weight per unit area pertains to pressure, which is related to forces applied across surfaces. The total weight of all components of a system refers to mass or gravitational force, not its distribution in volume. Weight in relation to temperature does not directly describe any established physical concept relevant to weight per volume. Thus, the accurate description of specific weight is indeed its representation as weight per volume.