Cambridge IGCSE Physics Notes 1.4: Density
Cambridge IGCSE Physics density notes on mass, volume, displacement, regular and irregular solids, liquids, and floating predictions.
Q: What does Cambridge IGCSE Physics Notes 1.4: Density cover?
A: It follows official Cambridge Physics section 1.4 for syllabuses 0625 and 0972, with Core ideas separated from Supplement depth.
Density compares mass with occupied volume and can be measured by pairing a mass measurement with the correct volume method.
The ideas that organise this section
- Use dimensions for regular solids and liquid displacement for irregular solids that sink.
- Keep mass and volume units compatible before division.
- For non-mixing substances, the lower-density material floats above the higher-density material.
Core route
Core candidates should be ready to describe, calculate, interpret, and apply the following:
- Calculate density from mass and volume.
- Describe density measurements for a liquid, regular solid, and irregular solid.
- Use density data to predict whether an object floats.
Supplement route
Extended candidates study all Core content and add the following depth:
- Use density data to predict the ordering of non-mixing liquid layers.
- Select and justify a method when the object shape or behaviour makes direct measurement difficult.
Formula route
- Relationship: density = mass / volume.
Write the relationship before substituting. Convert units first, keep extra figures during working, and round only the final answer to sensible precision.
Build a connected model
In Density, a strong answer connects the named quantity or model to observable evidence. Begin by defining the physical quantity in words or with its relationship. Identify which values are scalars and which require a direction. Represent the situation with a labelled diagram, graph, field pattern, ray or circuit when that makes the relationship visible. The representation is part of the reasoning: its labels, arrows and scale should agree with the written explanation.
For a calculation, write the governing relationship before substitution, convert prefixes and time units, keep unrounded values during working and attach the correct final unit. For a qualitative question, use a cause-link-consequence chain. Name what changes, state the physical mechanism that links the change to the system, and then give the measurable result. If two cases are compared, hold unrelated variables constant and use the same physical principle for both.
