- List of derived quantities
- Surface
- Volume
- Density
- Speed
- Acceleration
- Force
- Job
- Power
- Pressure
- Flow rate or volumetric flow
- Electric charge
- Electric resistance
- Electric potential difference
- Thermal conductance
- Caloric capacity
- Frequency
- Period
- References
The derived quantities are those whose units are a function of the existing ones for the fundamental quantities. The units used in these quantities are those recommended by the International System of Units (IU).
Thus, the derived physical quantities are expressed as a function of the fundamental ones: length (m), time (s), mass (kg), intensity of electric current (A), temperature (K), quantity of substance (mol) and luminous intensity (cd); all following the provisions of the International System of Units.
Velocity is one of the most important derived magnitudes when studying a physical or chemical phenomenon. Source: Pixabay.
Among the derived quantities we have the following: surface, volume, density, force, acceleration, velocity, work, concentration, viscosity, pressure, etc.
Unlike fundamental quantities, derivatives help not only to quantify the variables of a physical system, but also to describe and classify it. With these a more specific description of the bodies is obtained during an action or physical phenomenon.
With regard to chemistry, all units of molar concentrations (osmolarity, molarity and molality) are also derived quantities, since they depend on the mole, a fundamental quantity, and on the volume, a derived quantity.
List of derived quantities
Surface
Unit (SI) and depending on the unit of fundamental magnitude, length: m 2.
The area of a square is obtained by squaring the length of a side expressed in meters (m). The same is done with the surface of a triangle, a circle, a rhombus, etc. All are expressed in m 2. It is an extensive type quantity.
Volume
Unit (SI) and depending on the fundamental unit of magnitude, length: m 3.
The volume of a cube is obtained by cubing the length of a side expressed in meters (m). The volume of a cylinder, a sphere, a cone, etc., is expressed in m 3. It is an extensive type quantity.
Density
Unit (SI) and as a function of the units of fundamental magnitude: kg · m -3
It is calculated by dividing the mass of a body by the volume that the body occupies. Density is usually expressed in grams / cubic centimeters (g / cm 3). Density is an intensive type property.
Speed
Unit (SI) and as a function of the units of fundamental magnitude: ms -1
Velocity is the space traveled (m) in a unit of time (s). It is calculated by dividing the space traveled by a mobile by the time it takes to make this journey. Speed is a property of the intensive type.
Acceleration
Unit (SI) and as a function of the units of fundamental magnitude: ms -2
Acceleration is the increase or decrease that the speed of a mobile experiences in one second. Acceleration is a property of the intensive type.
Force
Unit (SI): Newton. As a function of the units of fundamental magnitude: kg · m · s -2
It is an action exerted on a body of mass 1 kilogram, to bring it out of rest, stop it or modify its speed in 1 second. The force is equal to the product of the mass of the mobile by the value of the acceleration it experiences. Force, depending on mass, is an extensive property.
Job
Unit (SI): July. Depending on the units of fundamental magnitude: kg · m 2 · s -2
Work is the energy that a force must develop to transport a body of mass 1 kilogram a distance of 1 meter. Work is the product of the force exerted by the distance traveled by the action of that force. This is an extensive type property.
Power
Unit (SI): watt (w = joule / s). Depending on the units of fundamental magnitude: kg · m 2 · s -3
A watt (w) is expressed as the power that is capable of delivering or generating an energy of one joule per second. It expresses the rate of energy generation per unit of time.
Pressure
Unit (SI): Pascal (Pa). Pa = N / m 2. As a function of the units of fundamental magnitude: kg · m -1 · s -2
Pressure is the force exerted by a liquid or gas per unit area of the container that contains it. For the same force, the larger the surface of the container, the lower the pressure experienced by said surface.
Flow rate or volumetric flow
Unit (SI) and as a function of the units of fundamental magnitude: m 3 s -1
It is the volume of fluid that passes through a cross section of a cylindrical tube per unit of time (second).
Electric charge
Unit (SI): coulomb. Depending on the units of fundamental magnitude: A · s (A = ampere).
A coulomb is defined as the amount of charge that is carried by an electric current of an intensity of one ampere in one second.
Electric resistance
Unit (SI): ohm (Ω). As a function of the units of fundamental magnitude: kg · m 2 · s -2 · A -2.
An ohm is the electrical resistance measured between two points of a conductor, when when there is a voltage difference of 1 volt between these points, an electric current of an intensity of 1 ampere is originated.
R = V / I
Where R is the resistance, V the voltage difference, and I the current intensity.
Electric potential difference
Unit (SI): volt (V). Depending on the units of fundamental magnitude: kg · m 2 · A -1 · s -3
The volt is the potential difference between two points on a conductor, which requires a work of one joule to transport a charge of 1 coulomb between these points.
Thermal conductance
Unit (SI): w · m -2 K -1. As a function of the units of fundamental magnitude: m 2 kg s -3
Thermal conductance is defined as the transfer of heat through a material when the temperature difference between the considered surfaces is one Kelvin, in time and unit surfaces.
Caloric capacity
Unit (SI): J · K -1. As a function of the units of fundamental magnitude: kg m s -2 K -1
Heat capacity (C) is the energy required to increase the temperature of a given substance by one degree Celsius or Kelvin.
Frequency
Unit (SI): hertz, hertz (Hz). As a function of the units of fundamental magnitude: s -1
One hertz represents the number of oscillations in a wave-like movement in a period of time of one second. It can also be defined as the number of cycles per second.
Period
In unit (SI) and in units of the fundamental quantity: s
It is the time between equivalent points of two successive waves.
Period (T) = 1 / f
Where f is the frequency of the wave motion.
References
- Serway & Jewett. (2009). Physics: for science and engineering with Modern Physics. Volume 2. (Seventh edition). Cengage Learning.
- Glenn Elert. (2019). International System of Units. The Physics Hypertextbook. Recovered from: physics.info
- Nelson, Ken. (2019). Physics for Kids: Scalars and Vectors. Ducksters. Recovered from: ducksters.com
- Angel Franco Garcia. (sf). Basic units. Recovered from: sc.ehu.es
- Ingemecánica. (sf). International system of measurement units. Recovered from: ingemecanica.com