Question

Calculate the mass of $8{m^3}$ of cement of density $2000\,\,kg/{m^3}.$

Answer 1

As in the question, we were given with density and volume of cement. So, to find mass of cement, dependence of mass on volume and density is to be used.
Density $= \dfrac{{Mass}}{{Volume}}$

Complete step by step answer:
We know that the density of any sustain is mass per unit volume.
So, Density $= \dfrac{{Mass}}{{Volume}}$
$\Rightarrow$Mass $=$Density $\times$ Volume
Now, In order to find mass of cement, we are given with
Density of cement $= 2000\,\,kg/{m^3}$
Volume of cement $= 8\,\,{m^3}$
Hence, Mass $=$Density $\times$ Volume
$= 2000 \times 8$
$= 16000\,\,kg$

Additional Information:
$\to$ The term density is generally denoted by the symbol $`\rho '$
i.e. $\rho = \dfrac{m}{V}$
Where m is mass and v is volume.
$\to$Different substances have different densities.
$\to$ To simplify, it is sometimes replaced by a dimensionless quantity i.e. “relative density” or “specific gravity”.
$\to$ “Relative density or “specific gravity” is the density of any substance with respect to that of water. It is the ratio of density of substances to the density of water.
$\to$ The density of a material varies with temperature and pressure.
$\to$ Density is an intensive property i.e. increasing the amount of any substances does not increase its density. Rathes, it increases its mass.
$\to$ It is units in the SI system are $kg\, - {m^{ - 3}}$ and in cgs are $g\, - c{m^{ - 3}}$.
$\to$ It is dimensional formula is $\left[ {M{L^{ - 3}}} \right].$

Note:
So, mass of cement is $16000\,\,kg$ one can also solve this question by unitary method which is
As density $= 2000\,\,kg/{m^3}$
This states that,
Mass of $1\,\,{m^3}$ of cement $= 2000\,\,kg$
Mass of $8\,\,{m^3}$ of cement $= 2000 \times 8\,\,kg$
$= 16000\,\,kg$.