In the formula γ = Sg x γw, what does γ represent?

• A. Specific weight
• B. Dry unit weight
• C. Density of material
• D. Wet unit weight

Answer: (A)

In the formula γ = Sg x γw, γ represents specific weight, which is a measure of the weight of a material per unit volume. Specific weight is calculated by multiplying the specific gravity (Sg) of a material by the weight of water (γw), usually expressed in units such as pounds per cubic foot or kilonewtons per cubic meter. This relationship indicates how the specific gravity effectively scales the weight of water to find the weight of the material in question.

Understanding specific weight is crucial in civil engineering and construction as it helps in evaluating material properties for design and analysis. Specific weight is frequently used in the context of soil mechanics, concrete production, and fluid mechanics, determining how materials behave under various conditions.

The other terms listed have distinct definitions. Dry unit weight refers specifically to the weight of solids without the influence of moisture, while wet unit weight considers both the solids and any moisture present. Density refers to mass per unit volume and does not directly incorporate the gravitational aspect inherent in specific weight. Thus, the correct answer ensures a clear understanding of the concept and application of specific weight in engineering contexts.