Units of measurement let us describe and compare length, weight, area, volume, density and other values. Units can be imperial or metric and they can be converted using conversion factors.
Part of MathsGeometry and measure
Density is a way of comparing how heavy different materials are.
It is a measurement of the amount of a substance contained in a certain volume.
The density of any solid is the mass of the object divided by its volume.
The formula for density is:
\(\text{density} = \frac{\text{mass}}{\text{volume}}\)
The standard units of density are kg/m3 and g/cm3.
Which material has the largest density?
Aluminium
\(\text{Density} = \frac{\text{mass}}{\text{volume}}\)
\(\text{Density} = \frac{13.5}{5}\)
Density = 2.7 g/cm3
Titanium
\(\text{Density} = \frac{18}{4}\)
Density = 4.5 g/cm3
Titanium has the largest density. One cubic centimetre of titanium is heavier than one cubic centimetre of aluminium.
The formula for density can be rearranged to calculate the mass or volume of an object.
\(\text{Mass} = \text{density} \times \text{volume}\)
\(\text{Volume} = \frac{\text{mass}}{\text{density}}\)
The density of air is 1.3 kg/m3. Calculate the mass of a balloon which holds 0.0035 m3 of air.
Mass = \(1.3 \times 0.0035\)
Mass = 0.00455 kg