Density

Key Stage 3

Meaning

Density is the amount of mass per unit volume of an object.

About Density

An object with a large amount of mass in a small volume is said to have a high density.

An object with a small amount of mass spread over a large volume is said to have a low density.

The units of density are kg/m³.

Solids are the most dense state of matter because there are a large number of particles in a certain volume and gases are the least dense state of matter because there are a small number of particles in a the same volume.

Density and Floating

If an object is more dense than water it will sink.

If an object is less dense than water it will rise through water and float on the surface.

Equation

Density = Mass/volume

\[\rho = \tfrac{m}{V}\] Where:

ρ = density

m = mass

V = volume

Example Calculations

5000kg of Iron has a volume of 0.635m2. Calculate the density of Iron.	Text	Text
Mass = 5000kg Volume = 0.635m3 \[\rho = \tfrac{m}{V}\] \[\rho = \tfrac{5000}{0.635}\] \[\rho = 7874kg/m<sup>3</sup>\]	Text	Text