Another kind of specific quantity, termed named specific quantity, is a generalization of the original concept. The divisor quantity is not restricted to mass, and name of the divisor is usually placed before "specific" in the full term (e.g., "
thrust-specific fuel consumption").
Named and unnamed specific quantities are given for the terms below.
Specific heat capacity, heat capacity per unit mass, unless another unit is named, such as mole-specific heat capacity, or volume-specific heat capacity
Specific relative angular momentum, of two orbiting bodies is angular momentum per unit reduced mass, or the vector product of the relative position and the relative velocity
Specific rotation of a chemical, angle of optical rotation α of plane-polarized light per standard sample with a path length of one decimeter and a sample concentration of one gram per millilitre
Specific speed, unitless figure of merit[clarification needed] used to classify pump impellers (pump-specific) and turbines (turbine-specific). Ratio of performance against reference pump that needs one unit of speed to pump one unit volume per one unit hydraulic head pressure. For a turbine, it is performance measured against a reference turbine that develops one unit of power per one unit speed per one unit of hydraulic head.
Specific properties are often used in reference tables as a means of recording material data in a manner that is independent of size or mass. This allows the data to be broadly applied while keeping the table compact.
Ranking, classifying, and comparing
Specific properties are useful for making comparisons about one attribute while cancelling out the effect of variations in another attribute. For instance, steel alloys are typically stronger than aluminum alloys but are also much denser. Greater strength allows less metal to be used, which makes the choice between the two metals less than obvious.[clarification needed] To simplify the comparison, one would compare the
specific strength (strength to weight ratio) of the two metals. A more everyday example relates to grocery shopping: a 2 kg package sells for a higher price than 1 kg package of the same foodstuff, but what matters is the "specific price", commonly called the unit cost (cost in currency units per kilogram).
Mnemonics and qualitative reasoning
In many instances, specific properties are more intuitive or are easier to remember than the original properties, whether in SI or imperial units. For instance, it is easier to conceptualize an acceleration of 2g than an acceleration of 19.6 meters per second squared.
Another kind of specific quantity, termed named specific quantity, is a generalization of the original concept. The divisor quantity is not restricted to mass, and name of the divisor is usually placed before "specific" in the full term (e.g., "
thrust-specific fuel consumption").
Named and unnamed specific quantities are given for the terms below.
Specific heat capacity, heat capacity per unit mass, unless another unit is named, such as mole-specific heat capacity, or volume-specific heat capacity
Specific relative angular momentum, of two orbiting bodies is angular momentum per unit reduced mass, or the vector product of the relative position and the relative velocity
Specific rotation of a chemical, angle of optical rotation α of plane-polarized light per standard sample with a path length of one decimeter and a sample concentration of one gram per millilitre
Specific speed, unitless figure of merit[clarification needed] used to classify pump impellers (pump-specific) and turbines (turbine-specific). Ratio of performance against reference pump that needs one unit of speed to pump one unit volume per one unit hydraulic head pressure. For a turbine, it is performance measured against a reference turbine that develops one unit of power per one unit speed per one unit of hydraulic head.
Specific properties are often used in reference tables as a means of recording material data in a manner that is independent of size or mass. This allows the data to be broadly applied while keeping the table compact.
Ranking, classifying, and comparing
Specific properties are useful for making comparisons about one attribute while cancelling out the effect of variations in another attribute. For instance, steel alloys are typically stronger than aluminum alloys but are also much denser. Greater strength allows less metal to be used, which makes the choice between the two metals less than obvious.[clarification needed] To simplify the comparison, one would compare the
specific strength (strength to weight ratio) of the two metals. A more everyday example relates to grocery shopping: a 2 kg package sells for a higher price than 1 kg package of the same foodstuff, but what matters is the "specific price", commonly called the unit cost (cost in currency units per kilogram).
Mnemonics and qualitative reasoning
In many instances, specific properties are more intuitive or are easier to remember than the original properties, whether in SI or imperial units. For instance, it is easier to conceptualize an acceleration of 2g than an acceleration of 19.6 meters per second squared.