Required Practical: Density

This lesson covers the Required Practical for determining the density of regular and irregular solid objects and liquids, as specified in the AQA GCSE Physics specification (4.3.1). This is one of the required practicals that you must understand in detail for the exam — you may be asked about the method, equipment, variables, sources of error, and how to improve accuracy.

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Overview of the Required Practical

The aim of this practical is to use appropriate apparatus to measure the density of:

1. A regular solid (e.g. a rectangular block or cylinder)
2. An irregular solid (e.g. a pebble or a key)
3. A liquid (e.g. water, salt solution, or oil)

The fundamental equation used throughout is:

density = mass / volume

p = m / V

Exam Tip: This is one of the eight required practicals for AQA GCSE Physics. You will not necessarily carry out this practical in the exam, but you MUST be able to describe the method, identify variables, evaluate sources of error, and suggest improvements. Questions on required practicals are worth significant marks.

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Part 1: Measuring the Density of a Regular Solid