## How are density and specific weight related?

Density is defined as mass per unit volume. It has the SI unit kg m-3 or kg/m3 and is an absolute quantity. Specific gravity is the ratio of a material’s density with that of water at 4 °C (where it is most dense and is taken to have the value 999.974 kg m-3). It is therefore a relative quantity with no units.

## How do you find density from specific weight?

Multiply the specific gravity by 1,000 to calculate the density of the substance in kilograms per cubic meter (kg/cubic meters) units. For example, the specific gravity of 0.84 corresponds to the density of 840 (0.84 x 1000) kg/cubic meters.

**What is the relationship between specific volume and density?**

The specific volume is the reciprocal of the density of the material, which is the mass per unit volume: r = (1/v) = (m/V). The “Specific Gravity” of a substance is the ratio of its mass to that of an equal volume of water at the same temperature and pressure.

### What does specific weight depend on?

Specific weight can also be defined as the product between density and gravitational acceleration. Specific weight, unlike density, is not absolute, it depends on the value of the gravitational acceleration (g), which varies depending on altitude and latitude.

### Does density equal specific weight?

4.6. Water has a density of 1 kg/l at 4°C. When the specific gravity is defined based on water at 4°C, then the specific gravity is equal to the density of the liquid. However, if the specific gravity is expressed at different temperatures, it will no longer be equal to the density.

**How is the density of a substance related to its specific gravity?**

Specific gravity is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material, often a liquid. If a substance’s relative density is less than one then it is less dense than water and similarly, if greater than 1 then it is denser than water.

## What is specific gravity How is it related to density?

Specific gravity is the density of a substance divided by the density of water. Since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density (but without any units).

## How do you calculate specific volume of air?

There are three common formulas used to calculate specific volume (ν): ν = V / m where V is volume and m is mass. ν = 1 /ρ = ρ-1 where ρ is density. ν = RT / PM = RT / P where R is the ideal gas constant, T is temperature, P is pressure, and M is the molarity.

**What is specific gravity of air?**

Since specific gravity is the ratio between the density (mass per unit volume) of an actual gas and the density of air – specific gravity has no dimension. The density of air at NTP is 1.205 kg/m3.

### How do you find the specific weight of a gas?

S = M / Mair , where S=gas specific gravity, M=gas molecular weight, Mair=28.96443 g/mole (molecular weight of standard air – CRC, 1983). The gas specific gravity calculation does not check for unreasonable inputs. Please enter positive values. “Inputs must be positive”.