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Published

mass density

vr.tr.mass-density · thing-q29539

Let an agent explain density by definition, measurement, typical values and applications such as buoyancy and materials selection.

Thing Registry Cross-cutting context XCT.QLT
Bundle → Layer → Finding → QuestionsClassifiersWhat it isWhy it existsDistinguishing featuresWhat robots and AI may and may not doMoral aspectsOwnersLinks to other meta-modelsIdentity and identifiersDirect propertiesRecognitionCapabilities and actionsHazards and failure modesStandards and interfacesContext of useSources

Bundle → Layer → Finding → Questions Filled

4 bundles · 8 layers · 8 findings · 16 questions

Concept What it is.

Calculate

Formula.

Calculate

Calculation.

  1. What is the density given this mass and volume? measurement
  2. Are the units consistent? boundary

Relative

Specific gravity.

Relative

Relative density.

  1. What is the relative density compared with water? measurement
  2. At which reference temperature? definition
Values Data.

Lookup

Tables.

Lookup

Reference values.

  1. What is the density of this material, according to reference data? provenance
  2. At what temperature and pressure? measurement

Conditions

Temperature effects.

Conditions

Temperature effects.

  1. How does density change with temperature for this substance? measurement
  2. Why is water densest near 4 degC? definition
Measurement Methods.

Methods

Instruments.

Methods

Measurement methods.

  1. Which method suits this sample, such as a hydrometer or pycnometer? definition
  2. Which standard applies? provenance

Displacement

Archimedes.

Displacement

Displacement method.

  1. How can volume be found by water displacement? action
  2. What errors arise? boundary
Applications Uses.

Buoyancy

Floating.

Buoyancy

Buoyancy.

  1. Will this object float in this liquid? boundary
  2. How does Archimedes principle explain it? definition

Materials

Selection.

Materials

Materials selection.

  1. Which material gives the needed strength for the lowest density? measurement
  2. Which database lists properties? provenance

Classifiers Filled

Family
Thing Registry
Category
Cross-cutting context
Entry kind
thing
Plane
XCT
Domain
XCT.QLT
Other names and narrower kinds
serum sodium level, mean corpuscular hemoglobin concentration, relative density, particle density, mass concentration, mass concentration of water, mass concentration of water vapour, mass concentration of water vapour at saturation, baricity, mass density of solid particles, fluid mass density, density of heavier fluid

What it is Filled

The mass of a substance per unit volume, symbol rho, measured in kilograms per cubic metre (kg/m3); water has a density of about 1000 kg/m3 near 4 degC, and related quantities include relative density (specific gravity) and mass concentration.

Why it exists Filled

Let an agent explain density by definition, measurement, typical values and applications such as buoyancy and materials selection.

Distinguishing features Filled

  • Mass per volume
  • Depends on temperature and pressure
  • Determines buoyancy
  • Characteristic of materials

What robots and AI may and may not do Filled

Must not

  • Ignore temperature effects when using density for quantity or safety calculations.
  • Mix units without stating them.
  • Present density as proof of authenticity or purity of a material without other tests.

Only with a human decision

  • Using a density figure to set a load, a dose or a trade valuation.

May

  • Calculate and convert densities, stating units, temperature and pressure.
  • Explain relative density and how it relates to mass concentration.

Moral aspects Filled

  • Wrong density figures can cause overloaded vessels and short-measured goods.

Who is affected

  • Buyers and sellers
  • Engineers and operators

Owners Filled

Steward

Nobody owns the quantity; metrology bodies maintain the units.

Links to other meta-models Filled

parent

  • Q107715 - registry parent class
  • Q137982797 - registry parent class
  • Q141187343 - registry parent class
  • Q141256417 - registry parent class
  • Q3387041 - registry parent class
  • Q41118 - registry parent class

related

  • physical quantity - category
  • kilogram per cubic metre - unit
  • buoyancy - effect
  • mass - quantity

What else AI and robots need to interact with it Filled

Identity and identifiers required Filled

  • Vercy registry: vr.tr.mass-density
  • Wikidata: Q29539 (https://www.wikidata.org/wiki/Q29539)
  • SI unit: kg/m3 derived unit

Direct properties not applicable Not applicable

  • density of water: about 1000 kg/m3 - near 4 degC

Plane XCT: no invented physical properties.

Recognition optional Filled

  • Units such as kg/m3 and g/cm3
  • Floating and sinking objects
  • Weight is a force, not density
  • Not visible; inferred from mass and volume or measured with hydrometers and densitometers.

Capabilities and actions required Filled

  • calculate density from mass and volume
  • look up density values with conditions
  • explain floating and sinking
  • convert between density units

Hazards and failure modes required Filled

  • Ignoring temperature effects
  • Unit conversion errors

Standards and interfaces required Filled

  • ISO and ASTM density test methods
  • OIML hydrometer recommendations

Context of use required Filled

  • Physics, engineering, chemistry and everyday estimation.
  • mass density
  • relative density and specific gravity
  • bulk and particle density
  • mass concentration in solutions
  • linear and area density

Sources Filled

  1. Wikidata item Q29539: mass density - identity and sense of the item
  2. Wikipedia: Density - general description of the item

Open questions

  • Should related densities be separate entries?
  • How should materials data be linked?
  • How should clinical concentrations be split off?

Machine files

Card as JSON Specification Card backlog vercy.card/1

Provenance

thing registry research (pass 2) · unreviewed

Built from: models/things/publications/thing-q29539/spec.json