Mass and volume determine the physical size, which is called density, and is the characteristic of each substance. Relative density calculator is obtained by the ratio of the density of the substance at a certain temperature to the density of water used as a reference at the same temperature or at a certain other temperature.

**CONTENT**

CONCEPT OF DENSITY

CONCEPT OF RELATIVE DENSITY

DENSITY AND RELATIVE DENSITY CALCULATOR

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**CONCEPT OF DENSITY**

Density, the mass of a substance per unit volume of a substance. The formula for density is d=M/V, where d is density, M is mass, and V is volume. Density is usually expressed in grams per cubic centimeter. Density provides a convenient means of obtaining body mass from its volume, and vice versa. Density is the ratio between mass and volume or the mass per unit volume. It is a measure of how many “things” an object has in a unit volume (cubic meters or cubic centimeters). Density is essentially a measure of the degree of tight binding of matter. The principle of density was discovered by the Greek scientist Archimedes. If you know the formula and understand its related units, it is easy to calculate.

**CONCEPT OF RELATIVE DENSITY**

Relative density (RD)is the ratio of the density of a substance to the density of water. It is also known as specific gravity (SG). Because it is a ratio, the relative density or specific gravity is a unitless value. If its value is less than 1, the density of the substance is lower than water, and it will float. If the relative density is exactly 1, the density is the same as water. The specific gravity of a liquid is almost always measured at the densest temperature (4°C or 39.2°F) relative to water; for gases, the reference is air at room temperature (20°C or 68°F). The term “relative density” is usually preferred in scientific usage.

**DENSITY AND RELATIVE DENSITY CALCULATOR**

(i) The concept of density:- Density = __ Mass __

Volume

e.g. A block of the worth volume 5.5m^{3} has a mass of 50g0kg find the density of ice

Volume of block = 5.5m^{3}, mass of block = 5060kg

: . D = ^{m}/_{v}= ^{5060}/_{5.5 }= 920kg/m^{3}

A silver cylindrical rod has a length of 0.8m and a radius 0.7m, find the density of the rod, if its mass is 33.40kg

**Note: **Volume wasn’t given but the parameters to find it was give there

Volume of Cylinder = πr^{2}h

= 3.14 x 0.7^{2} x 0.8

= 0.9853m^{3}

: . Density = __ Mass __ = __33.40__ = 3,389.8kg/m^{2}

Volume 0.9853

(ii) **Relative Density: **

Relative density = __Mass of any volume of substance __

Mass of an equal volume of water

Since mass is proportional to weight

: . Rm = __weight of any volume of substance __

weight of an equal volume of water