Question

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?

Answer 1

The density of the rock is `"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 = "42 mL - 30 mL" = "12 mL" = "12 cm"^3`

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