Question

A geology student found an irregularly shaped rock, with a mass of 28.63 grams, and placed it into a graduated cylinder with a volume of 13.31 mL water. If the water level increased to 19.73 mL after the rock was placed in, what is the density of the rock, in g/mL?

Answer 1

Answer : The density of the rock is, 4.459 g/ml

Explanation : Given,

Mass of the rock = 28.63 g

Initial volume of water = 13.31 ml

Increased volume of water = 19.73 ml

First we have to calculate the volume of the rock.

Volume of rock = Increased volume of water - Initial volume of water

Volume of rock = 19.73 ml - 13.31 ml = 6.42 ml

Now we have to calculate the density of rock.

Formula used :

$Density=\frac{Mass}{Volume}$

Now put all the given values in this formula, we get the density of the rock.

$Density=\frac{28.63g}{6.42ml}=4.459g/ml$

Therefore, the density of the rock is, 4.459 g/ml

Answer 2

Density is simply the ratio of mass over volume. In this case, the volume of the rock is the difference of after and before it was dropped into the cylinder.

volume = 19.73 mL – 13.31 mL = 6.42 mL

 

density = 28.63 g / 6.42 mL

density = 4.46 g/mL