# Question #337cb

##### 1 Answer

#### Explanation:

The thing to remember about the **density** of a given substance is that it tells you the mass of exactly **unit of volume** of that substance.

In your case, you know that the density of steel is equal to

So if you know that you need

#430 color(red)(cancel(color(black)("g"))) * "1 cm"^3/(7.8color(red)(cancel(color(black)("g")))) = color(darkgreen)(ul(color(black)("55 cm"^3)))#

The answer is rounded to two **sig figs**.

So remember, every time you have the density of a substance, you can use it as a **conversion factor** to find the mass of a given volume or the volume of a given mass.

For this example, you would have

#"mass " -> " volume:" " " "1 cm"^3/"7.8 g"#

#"volume " -> " mass:" " " "7.8 g"/"1 cm"^3#