Definition:Scalar Quantity/Examples
Examples of Scalar Quantities
Mass
The mass of a body is a measure of how much matter it contains.
Mass is equivalent to inertia.
Mass also determines the degree to which a body creates or is affected by a gravitational field.
It is a scalar quantity.
Volume
Volume is the measure of the extent of a body.
It has three dimensions and is specified in units of length cubed.
Density
Mass density is a physical quantity.
The mass density of a body is its mass per unit volume.
Speed
The speed of a body is a measure of the magnitude of its velocity, taking no account of its direction.
It is, therefore, a scalar quantity.
Temperature
Temperature is a physical property of matter that quantifies how hot or cold a body is.
It is a scalar quantity which can be mapped directly to the real number line.
Electric Potential
An electric potential is the amount of work needed to move a unit of electric charge from a given reference point to a specific point in an electric field without producing an acceleration.
The reference point is usually either Earth or a point at infinity, although any point can be used.
Electric Charge
Electric charge is a physical quantity of matter which causes it to experience a force when near other electrically charged matter.
It is a scalar quantity.
It has been discovered by experiment that the corresponding force depends on the magnitudes of those electric charges, their displacements from each other, and their velocities.
Entropy (Physics)
Entropy is a property of a thermodynamic system.
It quantifies the number $\Omega$ of microstates that are consistent with the macroscopic quantities that characterize the system.
The entropy of a system is equal to the expectation of the value:
- $k \ln P$
where:
- $k$ is a constant which relates the mean kinetic energy and absolute temperature of the system
- $P$ is the coefficient of probability of the system.
Sources
- 1951: B. Hague: An Introduction to Vector Analysis (5th ed.) ... (previous) ... (next): Chapter $\text I$: Definitions. Elements of Vector Algebra: $1$. Scalar and Vector Quantities
- 1992: Frederick W. Byron, Jr. and Robert W. Fuller: Mathematics of Classical and Quantum Physics ... (previous) ... (next): Volume One: Chapter $1$ Vectors in Classical Physics: $1.1$ Geometric and Algebraic Definitions of a Vector