Density is a measure of how tightly packed the molecules of a solid, liquid or gas are. The formula for calculating density is:
The dense city (density) was so dense they built motorways over any vegetation.
`m =` mass in kilograms (`kg`)
`V =` volume in cubic metres (`m`)
`D =` Density in kilograms per metre cubed (`kg//m^3`)
John wants to measure the density of a rock. He finds the volume with the apparatus shown below:
The mass of the rock was measured as being 36g. What is the density of the rock?
First convert everything to standard units
Mass of the rock `= 36g = 0.036\ kg`
Volume of rock `=36cm^3-18cm^3=18cm^3=0.000018m^3`
Density of the rock `=0.036/0.000018=2000\ kg//m^3`