Definition:Physical Quantity

Definition
This page contains several interrelated definitions, which may ultimately be circular.

Physical Quantity
A physical quantity is a physical property which can be quantified.

Physical Property
A physical property is any measurable property whose describes the state of a physical system.

Physical System
A physical system is a portion of the physical universe which has been chosen for investigation for a particular purpose.

Physical Process
A physical process is a physical system whose importance is in the way it changes over time.

Measurable Property
A measurable property is a property of a physical system which can be compared against a standard unit of measurement to provide a numerical value defining the quantity of that property.

The process of determining that quantity is called measurement.

Quantitative Property
A quantitative property is a property of a physical system which exists in a range of values corresponding with a number, such that the system can be described as having a particular number of a unit of measurement of that property.