# A rock has a mass of 8.0 grams. When the rock is placed in 30mL of water, the water level is raised to 42 mL. What is the density of the rock?

Sep 15, 2016

The density of the rock is ${\text{0.67 g/cm}}^{3}$.

#### Explanation:

The density (ρ) of anything is its mass ($m$) divided by its volume ($V$).

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The volume of the rock is equal to the volume of the water displaced

$V = {\text{42 mL - 30 mL" = "12 mL" = "12 cm}}^{3}$

ρ = m/V = "8.0 g"/("12 cm"^3) = "0.67 g/cm"^3