Question

The mass and volume of a body are $4.237\text{g}$ and $2.5{\text{cm}}^3$ respectively. The density of the material of the body in correct significant figures is

• A. $1.6948{\text{g/cm}}^3$
• B. $1.69{\text{g/cm}}^3$
• C. $1.7{\text{g/cm}}^3$
• D. $1.695{\text{g/cm}}^3$

Answer 1

The correct option is C $1.7{\text{g/cm}}^3$

We know that, the density of a material is given by,
$\rho =\frac{m}{V}$, where $m$ is mass and $V$ is volume.
$\Rightarrow \rho =\frac{4.237}{2.5}=1.6948{\text{g/cm}}^3$
We know that in multiplication or division, the final answer should have as many significant figures as in given data with minimum number of significant figures.
Here, $2.5{\text{cm}}^3$ have the minimum number of significant figures equal to two. Therefore, the final answer should have two significant figures.
On rounding off $1.6948{\text{g/cm}}^3$ to two significant figures, we get, $1.7{\text{g/cm}}^3$.