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Research draft

speed

vr.tr.speed · XCT.QLT

Let an agent explain and calculate speed, convert units, distinguish specific speeds such as sound and light, and address road speed limits and safety.

Thing Registry Cross-cutting context

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent explain and calculate speed, convert units, distinguish specific speeds such as sound and light, and address road speed limits and safety.

The rate at which an object covers distance, a scalar quantity measured in units such as metres per second or kilometres per hour, distinct from velocity which includes direction; specific speeds include the speed of sound, the speed of light, airspeed in aviation and legal speed limits on roads.

What it is for: Describing motion.

It can be calculate speed from distance and time; convert speed units; explain speed of sound and light; explain road speed limits and safety.

Distinguishing features

Scalar rate of motion

Distance over time

Many units

Reference speeds

What it looks like

Not physical; shown on speedometers and instruments.

Physical character

speed of light in vacuum: 299792458 m/s - exact by definition

speed of sound in air: about 343 m/s - at 20 C

How it is recognised

Speedometers and radar readings

Units such as km/h, m/s and knots

Velocity includes direction

Related models

is a kind of - category

physical quality

is a kind of - category

rate

is related to - physics

inertia

is related to - change of speed

acceleration

In practice

Families and kinds

instantaneous and average speed

speed of sound and light

airspeed types

road speed and limits

group and phase speed of waves

Standards and regulation

SI units

Road traffic speed limits

Aviation airspeed conventions

Failure modes and hazards

Unit confusion

Speeding and road deaths

Confusing speed with velocity

Also called

Tupolev Tu-444excessive speedspeed of soundindicated airspeedsound phase speedgroup speed of soundspeed of longitudinal sound wavesspeed of transversal sound wavesspeed of sound in plasmaspeeds of sound of the elementsflow speedcharacteristic speedmagneto-dynamic speedsubsonic speedspeed of propagation of wavesemergency speedmaximum safe cruising speedspeed of bodyspeed relative to waterfluid speedspeed of bubblesstall speedcomputational speedrate of climbcruising speedaverage particle speedparticle speedplayback speedmaximum speedairspeeddriving speedaverage speedslowwind speedground speedfastsupersonic speedwalking paceAlfvén wave speedroad speed

+28

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.speed-act

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Calculate Working with speed.

Speed is distance over time.

Compute

Calculation.

Compute

Calculation.

  1. What is the average speed for this distance and time? measurement
  2. What is the instantaneous speed? measurement

Units

Conversion.

Units

Conversion.

  1. How does this speed convert between km/h, mph, m/s and knots? measurement
  2. Which unit is standard here? provenance
Reference Special speeds.

Some speeds are fundamental.

Sound

Speed of sound.

Sound

Speed of sound.

  1. What is the speed of sound in this medium and temperature? measurement
  2. What are Mach numbers? definition

Light

Speed of light.

Light

Speed of light.

  1. Why is the speed of light constant and a limit? definition
  2. How does it define the metre? provenance
Road Speed limits.

Limits save lives.

Limits

Legal limits.

Limits

Legal limits.

  1. What speed limit applies on this road type here? provenance
  2. What are the penalties for speeding? provenance

Safety

Speed and injury.

Safety

Safety.

  1. How does speed affect stopping distance and crash severity? measurement
  2. Is the user asking how to evade enforcement? boundary
Domains Aviation and waves.

Domains define speeds.

Airspeed

Aviation.

Airspeed

Airspeed.

  1. How do indicated, true and ground speed differ? definition
  2. Why does it matter for pilots? definition

Waves

Wave speeds.

Waves

Wave speeds.

  1. How do phase and group speed differ? definition
  2. When do they diverge? boundary

What the second pass must settle

  • Should the speed of light be a separate entry?
  • How should speed limits be localised?
  • How should airspeed types be linked?