# Question ab103

Oct 17, 2017

$\text{70 g}$

#### Explanation:

The idea here is that the density of the object tells you the mass of ${\text{1 cm}}^{3}$ of this object.

In this case, you know that the density is equal to ${\text{7.2 g cm}}^{- 3}$, which means that ${\text{1 cm}}^{3}$ of this object has a mass of $\text{7.2 g}$.

This implies that your sample will have a mass of

10 color(red)(cancel(color(black)("cm"^3))) * "7.2 g"/(1color(red)(cancel(color(black)("cm"^3)))) = "72 g"

Now, notice that you have one significant figure for the volume of the object. This implies that the answer must be rounded to one significant figure.

"mass" = color(darkgreen)(ul(color(black)("70 g")))#