Specific weight

The specific weight, also known as the unit weight (symbol γ, the Greek letter gamma), is a volume-specific quantity defined as the weight W divided by the volume V of a material: $${\displaystyle \gamma =W/V}$$ Equivalently, it may also be formulated as the product of density, ρ, and gravity acceleration, g: $${\displaystyle \gamma =\rho \,g}$$ Its unit of measurement in the International System of Units (SI) is newton per cubic metre (N/m³), with base units of kg ⋅ m^-2 ⋅ s^-2. A commonly used value is the specific weight of water on Earth at 4 °C (39 °F), which is 9.807 kilonewtons per cubic metre or 62.43 pounds-force per cubic foot.^[1]