# How can you calculate mass if density and volume are known?

Jan 6, 2017

$\text{density"="mass"/"volume}$

$\text{mass"="density"xx"volume}$

#### Explanation:

Density is mass per unit volume. The equation is

$\text{density"="mass"/"volume}$.

If density and volume are already known, you can calculate mass by multiplying density by volume.

$\text{mass"="density"xx"volume}$

Example

The density of aluminum is ${\text{2.70 g/cm}}^{3}$. A sample of aluminum with a volume of $\text{12.5 cm"^3}$. What is its mass?

$\text{mass"="density"xx"volume}$

$\text{mass"=2.70"g"/cancel"cm"^3xx12.5cancel"cm"^3="33.8 g}$

The mass of ${\text{12.5 cm}}^{3}$ of aluminum is $\text{33.8 g}$

The following device is helpful when determining density, mass, or volume, when two of the others are known. Cover the variable that you want to calculate, then do the calculation for the other two variables as shown on the triangle.