Physlib.ClassicalMechanics.Mass.MassUnit
Units on Mass
A unit of mass corresponds to a choice of translationally-invariant metric on the mass manifold (to be defined diffeomorphic to `ℝ≥0`). Such a choice is (non-canonically) equivalent to a choice of positive real number. We define the type `MassUnit` to be equivalent to the positive reals.
On `MassUnit` there is an instance of division giving a real number, corresponding to the ratio of the two scales of mass unit.
To define specific mass units, we first state the existence of a a given mass unit, and then construct all other mass units from it. We choose to state the existence of the mass unit of kilograms, and construct all other mass units from that.
Division of MassUnit
The scaling of a mass unit
Specific choices of mass units
To define a specific mass units. We first define the notion of a kilogram to correspond to the mass unit with underlying value equal to `1`. This is really down to a choice in the isomorphism between the set of metrics on the mass manifold and the positive reals. From this choice of kilograms, we can define other length units by scaling kilograms.
Relations between mass units
31 declarations
The value of a mass unit is non-zero ()
For any mass unit , its associated numerical value is non-zero. In the context of `Physlib`, a `MassUnit` is defined as being equivalent to the positive real numbers , and represents the real number associated with that unit.
The value of a mass unit is positive ()
For any mass unit , its associated numerical value is strictly positive (). In the context of `Physlib`, a `MassUnit` is defined as being equivalent to the positive real numbers , and represents the real number associated with that unit.
Default `MassUnit` is (kilogram)
The type `MassUnit` is provided with a default element, specified as the unit whose underlying numerical value is . In the context of this library, this default element represents the kilogram.
Division of mass units
The division operation for mass units and is defined such that their ratio is a non-negative real number , calculated as the quotient of their underlying numerical values .
for mass units
For any two mass units and , their ratio is equal to the quotient of their underlying numerical values as a non-negative real number in .
for mass units
For any two mass units and , the ratio of to is non-zero. That is, where the result is a non-negative real number in .
for mass units
For any two mass units and , the ratio of to is strictly positive. That is, where the result is a non-negative real number in .
for mass units
For any mass unit , the ratio of to itself is equal to . That is, where the result is a non-negative real number .
for mass units
For any two mass units and , the ratio of to is equal to the reciprocal (multiplicative inverse) of the ratio of to . That is, , where the division represents the non-negative real ratio between two mass units in .
for mass units
For any three mass units , , and , the product of the ratio of to and the ratio of to is equal to the ratio of to . That is, , where the division represents the non-negative real ratio between two mass units.
The ratio for mass units
For any mass unit and any positive real number , let denote the mass unit scaled by the factor . The ratio of this scaled unit to the original unit is equal to . That is, , where the division represents the non-negative real ratio between the two mass units.
for mass units
For any mass unit and any positive real number , the ratio of the unit to the unit scaled by (denoted ) is equal to . Here, the division of two mass units represents their ratio as a non-negative real number in .
Scaling a mass unit by equals the original unit
For any mass unit , the result of scaling by the factor is equal to .
for Mass Units
For any two mass units and any positive real numbers (where ), the ratio of the scaled units satisfies the identity: where denotes the unit scaled by the factor , and the division of two mass units represents their ratio as a non-negative real number in .
for Mass Units
For any mass unit and any positive real numbers (where and ), scaling the unit by and then scaling the resulting unit by is equivalent to scaling the original unit by the product : where denotes the mass unit scaled by the factor .
The mass unit of kilograms
The kilogram is defined as the unit of mass corresponding to the value in the type `MassUnit`, which is represented by the set of positive real numbers . This choice serves as the reference scale for all other mass units.
The mass unit of micrograms ( kg)
The mass unit of micrograms is defined as times the mass unit of kilograms. In the `MassUnit` type, which is represented by the positive real numbers where kilograms is the reference unit (value 1), a microgram corresponds to the element obtained by scaling the kilogram unit by a factor of .
The mass unit of milligrams ( kg)
The mass unit of milligrams is defined as times the mass unit of kilograms. In the `MassUnit` type, which is modeled by the positive real numbers with kilograms as the reference unit (value 1), a milligram is the element obtained by scaling the kilogram unit by a factor of .
The mass unit of grams ( kg)
The mass unit of grams is defined as times the mass unit of kilograms. Specifically, in the `MassUnit` type, a gram is the element obtained by scaling the reference unit of kilograms by a factor of .
The mass unit of ounces ( kg)
The mass unit of (avoirdupois) ounces is defined as times the mass unit of kilograms. Specifically, in the `MassUnit` type (which is represented by the set of positive real numbers where kilograms serve as the reference unit with value ), an ounce is the element obtained by scaling the kilogram unit by the factor .
The mass unit of pounds ( kg)
The mass unit of (avoirdupois) pounds is defined as times the mass unit of kilograms. Specifically, in the `MassUnit` type (which is represented by the set of positive real numbers ), a pound is the element obtained by scaling the reference unit of kilograms by the factor .
The mass unit of stones ( pounds)
The mass unit of stones is defined as times the mass unit of pounds. Specifically, in the `MassUnit` type (which is represented by the set of positive real numbers ), a stone is the element obtained by scaling the previously defined unit of pounds by a factor of .
Mass unit of a quarter ( pounds)
The mass unit of quarters is defined as times the mass unit of pounds. Specifically, within the `MassUnit` type (which is identified with the set of positive real numbers ), a quarter is the element obtained by scaling the value of a pound by a factor of .
The mass unit of hundredweights ( pounds)
The mass unit of hundredweights is defined as times the mass unit of pounds. Within the `MassUnit` type, which is represented by the set of positive real numbers , the hundredweight is the element obtained by scaling the unit of pounds by a factor of .
Short ton mass unit ()
The short ton is a unit of mass defined as 2000 times the value of the mass unit of pounds. Within the `MassUnit` framework, where mass units are represented by the set of positive real numbers relative to a reference kilogram, the short ton corresponds to the element obtained by scaling the unit of pounds by a factor of .
Metric ton unit ()
The metric ton is defined as the unit of mass obtained by scaling the reference unit of kilograms by a factor of .
Long ton unit ()
The mass unit of long tons is defined as times the mass unit of pounds. In the `MassUnit` type, which is represented by the set of positive real numbers , a long ton (also known as a shortweight ton) is the element obtained by scaling the unit of pounds by a factor of .
Nominal solar mass unit ()
The nominal solar mass unit is defined as the unit of mass obtained by scaling the reference unit of kilograms by a factor of .
The ratio of the mass unit of pounds to the mass unit of ounces is equal to . Formally, , where the division of these two mass units results in a non-negative real number .
The ratio of the mass unit of short tons to the mass unit of kilograms is equal to . Formally, , where the division of these two mass units results in a non-negative real number representing the numerical scale of short tons relative to the reference unit of kilograms.
The ratio of the mass unit of long tons to the mass unit of kilograms is equal to . Formally, , where the division of these two mass units results in a non-negative real number .
