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InformationUDP datagram service

UDP exchanges addressed messages without adding reliable stream delivery.

DefinitionInformationDNS names, records and caching

DNS distributes typed resource records through a delegated naming hierarchy.

DefinitionInformationCombinational digital-circuit model

A combinational output depends on current valid inputs after a bounded settling delay.

ModelInformationBoolean gates and truth tables

Logic gates compute Boolean functions with truth values 0 and 1.

DefinitionInformationClocked storage and sequential state

Sequential circuits retain state, so current inputs alone do not determine their behavior.

ModelInformationStored programs and instruction sets

Stored instructions control computation through a specified hardware/software interface.

ModelPhysicsDisplacement, distance and average speed

Displacement compares endpoints; distance measures the travelled path.

ModelPhysicsConstant-acceleration kinematics

Closed formulas require constant acceleration over the interval.

ModelPhysicsInertial reference frames and inertia

Newtonian force balances need an inertial frame or explicit inertial terms.

ModelPhysicsCircular motion and centripetal acceleration

A constant speed can still have an acceleration.

ModelPhysicsMass, gravitational weight and apparent weight

Mass is in kilograms; gravitational weight is a force.

ModelPhysicsNormal forces and tension

Contact geometry determines the force direction.

ModelPhysicsFree-body diagrams and system boundaries

List forces on the selected body once.

ModelPhysicsStatic and kinetic dry friction

Static friction is a responsive force with an approximate limit.

ModelPhysicsFluid drag and terminal speed

Terminal speed depends on the chosen drag model.

ModelPhysicsImpulse and momentum transfer

Time-integrated net force changes momentum.

ModelPhysicsElastic and inelastic collisions

Momentum conservation and kinetic-energy conservation are different.

ModelPhysicsConservative forces and potential energy

Potential-energy differences encode path-independent work.

ModelPhysicsMechanical-energy conservation and dissipation

Mechanical energy is only part of the total energy.

ModelPhysicsHooke’s spring model and elastic energy

A linear spring restores displacement toward equilibrium.

ModelPhysicsMechanical power

Power measures the rate of work or energy transfer.

ModelPhysicsRigid-body rotational kinetic energy

Rotation stores kinetic energy determined by mass distribution.

ModelPhysicsRolling without slipping

No slip constrains velocity at the contact point.

ModelPhysicsStatic equilibrium and torque balance

Zero net force alone does not prevent rotation.

ModelPhysics · Earth & cosmosYoung, shear and bulk elastic moduli

Stress and strain need a loading geometry and a constitutive range.

ModelPhysicsDensity and fluid pressure

Density is mass per volume; pressure is normal force per area.

ModelPhysicsAbsolute, gauge and differential pressure

A zero gauge reading need not be a vacuum.

ModelPhysicsPascal’s principle and ideal hydraulics

A pressure change is transmitted; pressure need not be equal at different heights.

ModelPhysicsNewtonian viscosity and Poiseuille flow

Viscosity relates shear stress to velocity gradient.

ModelPhysics · ChemistrySurface tension and capillary rise

Interface forces can support pressure jumps and capillary columns.

Model
ModelSource checked

Mechanical power

Physics

Power measures the rate of work or energy transfer.

Key knowledge

Average power is work divided by the time interval; instantaneous mechanical power is dW/dt. For a force acting at a point moving with velocity v, its power is F·v. A force perpendicular to that velocity transfers no mechanical energy through that point even if it changes the direction of motion.

Values and equations

P_average=ΔW/Δt; P=dW/dt=F·v

P,P_average
Instantaneous and average power W
W,ΔW
Work and work over the interval J
t,Δt
Time and nonzero interval duration s
F
Applied force N
v
Velocity of its application point m s⁻¹

Conditions and scope

  • Use the velocity of the force’s application point in the same reference frame.
  • Extended deformable contacts can transfer energy through multiple points; the centre-of-mass velocity alone need not describe all work. Signed power distinguishes delivery from removal of energy.
Sources · 1

References

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

  1. University Physics Volume 1, §7.4: powerSamuel J. Ling, Jeff Sanny and William Moebs — OpenStax, Rice University, University Physics (2016)Textbook chapteropenstax.orgRead source

Evidence and review

Read §7.4 average/instantaneous definitions7.10–7.11 and force–velocity power derivation. Retain application-point and reference-frame scope; no claim that all energy transfer is point-force work.

2026-10-10 · /root/audit_life_earth_chemistry — independent Chemistry/Life/Earth editor. Independent AI editorial review of this entry's statements, equations, applicability conditions and source coverage. Source checks apply to these claims within their stated limits.

Related reference entries

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

Showing 1–5 of 5 relationships

Scientific relationships · 5 / 5

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

  1. Uses definition
    Relationship sources · 1

    Linked statements

    • Average power is work divided by the time interval; instantaneous mechanical power is dW/dt. For a force acting at a point moving with velocity v, its power is F·v. A force perpendicular to that velocity transfers no mechanical energy through that point even if it changes the direction of motion.

    This relation concerns the stated mechanical power claim and its conditions; it does not assert an unqualified prerequisite or an additional theorem.

  2. Uses definition
    Relationship sources · 1

    Linked statements

    • Average power is work divided by the time interval; instantaneous mechanical power is dW/dt. For a force acting at a point moving with velocity v, its power is F·v. A force perpendicular to that velocity transfers no mechanical energy through that point even if it changes the direction of motion.

    This relation concerns the stated mechanical power claim and its conditions; it does not assert an unqualified prerequisite or an additional theorem.

  3. Uses definition
    Relationship sources · 1

    Linked statements

    • For one travelling sinusoidal small-transverse-displacement wave on a uniform taut ideal string, average transmitted mechanical power is μA²ω²v/2, with v=√(Tension/μ). Doubling amplitude at fixed frequency and string parameters quadruples this average power. This is energy flow along the string, rather than the transverse particle speed.

    This relation concerns the stated energy carried by a sinusoidal string wave claim and its conditions; it does not assert an unqualified prerequisite or an additional theorem.

  4. Uses definition
    Relationship sources · 1

    Linked statements

    • Sound intensity is average acoustic energy flux per area. A progressive sinusoidal plane wave in a lossless fluid has I=p_peak²/(2ρc_s)=p_rms²/(ρc_s). Sound intensity level is L_I=10log₁₀(I/I_ref), commonly with I_ref=10⁻¹² W m⁻². A tenfold intensity increase is 10 dB; intensity level, sound-pressure level and perceived loudness are distinct.

    This relation concerns the stated sound intensity and decibel level claim and its conditions; it does not assert an unqualified prerequisite or an additional theorem.

  5. Related to
    Relationship sources · 1

    Linked statements

    • With passive sign convention, current entering an element’s higher-potential terminal gives absorbed instantaneous power p=vi and energy ∫pdt. For a positive constant resistance, p=i²R=v²/R≥0: electrical energy becomes internal energy and other dissipation channels. AC average power is the average of vi, rather than generally the product of rms voltage and rms current.

    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.

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