gewichtspecifiek

Gewichtspecifiek is a term used in Dutch to denote the specific weight of a material, that is, the weight per unit volume. It is sometimes written as gewichtspecifiek, while in other texts the more common phrase is het specifieke gewicht. The concept is closely related to the physical property known in English as specific weight or weight density and is distinct from mass density.

The specific weight γ is defined as the product of mass density ρ and the local gravitational acceleration g: γ = ρ g. Because weight is a force, γ has units of newtons per cubic meter (N/m³). In practical calculations, the specific weight is used to relate fluid or material height to pressure, for example in hydrostatics where hydrostatic pressure is p = γ h, with h the vertical depth. The value of γ depends on both the material and the strength of the local gravity; thus it varies with location (for example on different planets) even if the density remains the same.

In engineering and physics, gewichtspecifiek is commonly employed in problems involving buoyancy, earthworks, foundations, and fluid statics. It helps distinguish how much weight a given volume of material exerts, as opposed to how much matter it contains. The concept is often contrasted with density (ρ), which measures mass per volume and is independent of gravity. Typical examples illustrate the idea: water has γ ≈ 9.81 kN/m³, air at sea level about γ ≈ 12 N/m³, and concrete with ρ ≈ 2400 kg/m³ yields γ ≈ 23.5 kN/m³.