Physics - Masurements

Topic 1

How close a measurement is to the true value.

Accuracy

Add all values together, then divide by the number of values.

Average (mean)

Mass divided by volume. Measured in kg/m³.

Density

Finding the volume of an irregular solid by measuring how much liquid it displaces.

Displacement method

An experiment where only one variable is changed at a time.

Fair test

A mathematical equation showing the relationship between variables.

Formula

The SI base unit of mass.

Kilogram (kg)

A quantity measuring distance, measured in metres (m).

Length

The amount of matter in an object, measured in kilograms (kg).

Mass

The curved surface of a liquid in a container. Read the lowest point.

Meniscus

The SI base unit of length.

Metre (m)

A device used to measure very small distances, often to ±0.01 mm precision.

Micrometer

How finely a measurement is recorded, such as its decimal places.

Precision

Something measurable, usually expressed as a number and a unit.

Quantity

Measuring the same quantity again. Repeats can be averaged.

Repeat measurement

The SI base unit of time.

Second (s)

The internationally agreed system of measurement, also called metric.

SI (Système International)

The important digits in a measurement. For example, 3.2 has two significant figures.

Significant figures

A measurable quantity expressed in seconds (s).

Time

An agreed standard used to measure a physical quantity.

Unit

The numerical magnitude of a measurement, written with the correct unit.

Value

The amount of space an object or substance occupies, often measured in m³ or cm³.

Volume

The variable that you deliberately change in an experiment.

Independent variable

The variable that you measure or observe in an experiment.

Dependent variable

The variables kept the same to make an experiment fair.

Controlled variables

How consistent repeated measurements are with each other.

Reliability

The amount of space occupied by a regularly shaped object, calculated using a suitable formula.

Calculated volume

The total of all measurements divided by the number of measurements.

Mean

The unit used for measuring the amount of space an object occupies.

Cubic metre (m³)