Density | Letaio

CIE IGCSE · Physics 0625 · 2026–2028

1Motion, forces and energy

1.1Physical quantities and measurement techniques
1.2Motion
1.3Mass and weight
1.4Density
1.5Forces
1. 1.5.1Effects of forces
2. 1.5.2Turning effect of forces
3. 1.5.3Centre of gravity
1.6Momentum
1.7Energy, work and power
1. 1.7.1Energy
2. 1.7.2Work
3. 1.7.3Energy resources
4. 1.7.4Power
1.8Pressure

2Thermal physics

2.1Kinetic particle model of matter
1. 2.1.1States of matter
2. 2.1.2Particle model
3. 2.1.3Gases and the absolute scale of temperature
2.2Thermal properties and temperature
1. 2.2.1Thermal expansion of solids, liquids and gases
2. 2.2.2Specific heat capacity
3. 2.2.3Melting, boiling and evaporation
2.3Transfer of thermal energy
1. 2.3.1Conduction
2. 2.3.2Convection
3. 2.3.3Radiation
4. 2.3.4Consequences of thermal energy transfer

3Waves

3.1General properties of waves
3.2Light
1. 3.2.1Reflection of light
2. 3.2.2Refraction of light
3. 3.2.3Thin lenses
4. 3.2.4Dispersion of light
3.3Electromagnetic spectrum
3.4Sound

4Electricity and magnetism

4.1Simple phenomena of magnetism
4.2Electrical quantities
1. 4.2.1Electric charge
2. 4.2.2Electric current
3. 4.2.3Electromotive force and potential difference
4. 4.2.4Resistance
5. 4.2.5Electrical energy and electrical power
4.3Electric circuits
1. 4.3.1Circuit diagrams and circuit components
2. 4.3.2Series and parallel circuits
3. 4.3.3Action and use of circuit components
4.4Electrical safety
4.5Electromagnetic effects
1. 4.5.1Electromagnetic induction
2. 4.5.2The a.c. generator
3. 4.5.3Magnetic effect of a current
4. 4.5.4Force on a current-carrying conductor
5. 4.5.5The d.c. motor
6. 4.5.6The transformer

5Nuclear physics

5.1The nuclear model of the atom
1. 5.1.1The atom
2. 5.1.2The nucleus
5.2Radioactivity
1. 5.2.1Detection of radioactivity
2. 5.2.2The three types of nuclear emission
3. 5.2.3Radioactive decay
4. 5.2.4Half-life
5. 5.2.5Safety precautions

6Space physics

6.1The Earth and the Solar System
1. 6.1.1The Earth
2. 6.1.2The Solar System
6.2Stars and the Universe
1. 6.2.1The Sun as a star
2. 6.2.2Stars
3. 6.2.3The Universe

Entry 1.4

Big question

Why does a steel ship float while a steel bolt sinks?

01Density is mass per unit volume

Density $ρ = \frac{m}{V}$ , measured in $g/cm^{3}$ or $kg/m^{3}$ . It is a property of the material, not the size of the object: a drop of water and a swimming pool of water have the same density.

Measuring an irregular solid

A stone has mass $54 g$ . Lowered into a measuring cylinder, the water level rises from $40 cm^{3}$ to $60 cm^{3}$ . Find the density of the stone.

Find the volume from the rise in water level: $V = V_{final} - V_{initial}$ .
Write the equation: $ρ = \frac{m}{V}$ .
Substitute the values and include the unit.

Your working

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Answer

$V = 60 - 40 = 20 cm^{3}$ . $ρ = \frac{54}{20} = 2.7 g/cm^{3}$ .