How tightly packed the mass is: ρ = m ÷ V, the particle model of solids, liquids and gases, and changing g/cm³ into kg/m³.
What you will learn
- Calculate density, mass or volume with ρ = m ÷ V
- Describe the particles in a solid, a liquid and a gas
- Convert between g/cm³ and kg/m³
Mass in every cubic metre
Density tells you how much mass is packed into each unit of volume.
density = mass ÷ volume
ρ = m ÷ V
Mass in kg, volume in m³, density in kg/m³ (AQA: recall this one; Edexcel and OCR: it is on the list you learn too). In the lab, grams and cm³ give g/cm³.
- A 0.54 kg block has a volume of 0.0002 m³
- ρ = 0.54 ÷ 0.0002
- ρ = 2700 kg/m³ (it is probably aluminium)
Rearranged: mass m = ρ × V, and volume V = m ÷ ρ. The volume of a rectangular block is length × width × height.
The rest of this lesson and its 8 practice questions are locked.
In this lesson
- Mass in every cubic metre
- Why gases are so light
- g/cm³ and kg/m³
- Try it: Your first density
8 practice questions, marked as you go; about 20 minutes in all.
In this unit: Particle model, density and gas pressure
Density and its required practical, changes of state, specific latent heat, and the particle model of gas pressure, including p₁V₁ = p₂V₂.