# A block of wood 3.0cm on each side has a mass of 27g. What is the density of this block? Answer: 1.0 #"g/cm"^3#.

##### 1 Answer

#### Answer:

The 3.0 × 3.0 × 3.0 comes from the formula for the volume of a rectangular solid.

#### Explanation:

You can read about how to calculate density here.

The formula is

#"Density" = "Mass"/"Volume"#

You have to know the **mass** and the **volume** to calculate the density.

You know that the **mass** is 27 g.

Now you have to calculate the **volume**.

You know that your sample is a block that is 3.0 cm on each side.

The formula for the volume of a rectangular solid is

#V = l×w×h#

In this case,

In each of your calculations, the number of decimals is controlled by the number of significant figures.

Every number you use in your calculations has 2 significant figures, so you can have only 2 significant figures in your answers.