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Showing 61–90 of 1709 reference entries

Physics · MeasurementElectric current

Current measures charge crossing a chosen surface per unit time.

DefinitionPhysicsElectric field and force

An electric field assigns force per unit test charge.

DefinitionPhysicsMagnetic force on a moving charge

Magnetic force depends on charge motion relative to the field.

ModelPhysicsOhm's law and its domain

A linear current-voltage relation requires suitable conditions.

Empirical findingPhysicsFirst law of thermodynamics

Keep the heat and work sign convention explicit in an energy balance.

ModelPhysicsSecond law: isolated-system entropy

Apply entropy increase to the whole isolated system.

ModelPhysics · ChemistryIdeal-gas equation of state

A simple gas model relates pressure, amount, volume and temperature.

ModelPhysicsPhoton energy and frequency

One photon's energy is proportional to its frequency.

ModelPhysics · Mathematics & logicInvariant spacetime interval

Lorentz transformations preserve a combined space-time separation.

ModelPhysicsNewton's third law

Interaction forces act on different bodies in equal and opposite pairs.

ModelPhysicsAngular momentum and torque

Torque changes angular momentum about a specified origin.

ModelPhysicsHydrostatic pressure

Static fluid pressure rises with depth under gravity.

ModelPhysicsArchimedes' buoyancy principle

The hydrostatic upward force equals displaced-fluid weight.

ModelPhysicsMaxwell equations in free space

Four field equations connect electric and magnetic fields with charge and current.

ModelPhysicsSchrödinger time evolution

A quantum wavefunction evolves according to its Hamiltonian.

ModelPhysicsBorn position probability

A normalized wavefunction assigns probabilities to position intervals.

ModelPhysics · MeasurementElementary charge

The elementary charge has an exact SI numerical value.

DefinitionPhysics · MeasurementBoltzmann constant

The Boltzmann constant has an exact SI numerical value.

DefinitionMeasurement · Chemistry · PhysicsAvogadro constant

The mole is linked to a specified number of entities.

DefinitionMeasurement · PhysicsSI defining luminous efficacy

A specified frequency fixes the photometric SI reference.

DefinitionChemistryAtoms and elemental identity

The proton count of an atomic nucleus identifies its chemical element.

DefinitionChemistryIsotopes and mass number

Isotopes share a proton count but have different neutron counts.

DefinitionChemistryPeriodic organization of the elements

Atomic-number order reveals recurring patterns in electron structure and chemical properties.

ModelChemistryChemical bonds

Bonding describes interactions that bind atoms into molecules or extended structures.

DefinitionChemistry · MeasurementMole and amount of substance

The mole counts specified entities using the exact Avogadro constant.

DefinitionChemistryReaction stoichiometry

Balanced coefficients relate the amounts consumed and produced by a reaction.

MethodChemistryBalancing atoms and electric charge

A chemical equation must preserve each element's atom count and the total charge.

MethodChemistryDynamic chemical equilibrium

At equilibrium, opposing reactions continue without net composition change.

ModelChemistryBrønsted acids and bases

In the Brønsted description, an acid donates a proton and a base accepts it.

DefinitionChemistryGibbs energy and thermodynamic direction

Gibbs-energy change distinguishes thermodynamic favourability from reaction speed.

Model
ModelSource checked

Archimedes' buoyancy principle

Physics

The hydrostatic upward force equals displaced-fluid weight.

Key knowledge

For a body partially or fully immersed in a static fluid, the hydrostatic buoyant force equals the weight of fluid displaced. With uniform fluid density and gravity, its magnitude is F_B = ρ_fluid g V_displaced.

Values and equations

F_B = ρ_fluid g V_displaced

F_B
Upward hydrostatic buoyant-force magnitude N
ρ_fluid
Uniform displaced-fluid mass density kg m⁻³
g
Uniform gravitational-acceleration magnitude m s⁻²
V_displaced
Volume of fluid displaced by the submerged body portion m³

Conditions and scope

  • Fluid pressure reaches the surrounding wetted surface; sealed contact with the bottom is outside this model.
  • Use the submerged displacement volume, not automatically the body's whole volume.
  • Surface-tension forces and dynamic lift are excluded; buoyancy equals body weight only when the full vertical force balance allows it.
Sources · 2

References

Sources retain their recorded scope. A source link alone does not establish verification of every statement.

  1. University Physics, volume 1: Archimedes' Principle and BuoyancySamuel J. Ling, Jeff Sanny and William Moebs / OpenStax, Rice UniversityTextbook chapteropenstax.orgRead source
  2. Fluid Mechanics · BuoyancyGautam Biswas and Suman Chakraborty · NPTEL Fluid MechanicsCourse notesarchive.nptel.ac.inRead source

Evidence and review

OpenStax 14.4: pressure-force argument, displaced-fluid weight and partial immersion.

2026-10-10 · Static-fluid pressure contribution only; no general claim that every immersed body floats or has this force under arbitrary contact conditions.

Foundational review

2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.

Sources from other places

Scope or convention differs

Hydrostatic buoyancy in homogeneous fluid equals the weight of displaced fluid, including partial immersion.

The wetted-surface argument supports the formula; sealed-bottom contact and surface tension require separate forces.

  • Indian Institute of Technology Kanpur · NPTEL

Related reference entries

Explore relationships within this area of study and its connections to other areas.

Showing 1–2 of 2 relationships

Scientific relationships · 2 / 2

The relationship type describes the connection. Its linked statements, sources and conditions define the scope.

  1. Derived from
    Relationship sources · 1

    The net hydrostatic pressure force equals displaced-fluid weight under the stated static-fluid and boundary assumptions.

  2. Related to
    Relationship sources · 1

    Linked statements

    • For a specified body and regime, an approximate quadratic drag magnitude is F_D=ρC_DAv_rel²/2, opposing relative motion through the fluid. A vertical falling body reaches a terminal speed when gravity, drag and any buoyancy balance. Neglecting buoyancy in a constant-coefficient model gives v_T=√(2mg/(ρC_DA)).

    The two records describe related physical or metrological models or distinctions; the present claim does not require every hypothesis or result in the linked record.

Entry detailsPermanent link to this entry ↗
Record identity
physics-buoyancy
Revision
core.1
Structured reference record
Essential core · first collection · University core expansion