# Question #543b6

##### 1 Answer

Feb 15, 2015

The thing I want to point out is that density is defined as mass over unit of volume. Therefore, regardless of what actual unit you use to express it, you must always have a unit of mass divided by a unit of volume.

The density of aluminium should therefore be expressed in *length*, not per volume.

That being said, you go about solving this problem by using the formula for density

In this case,

SInce you're dealing with a perfect cube, the volume can be expressed as

Therefore,