force
(physics) the influence that produces a change in a physical quantity
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 handle forces as vector quantities with magnitude, direction and point of application, and state them with units.
In physics, an influence that changes the motion or shape of a body, measured in newtons, such as gravity, friction, aerodynamic lift or chemical attraction between atoms.
What it is for: Explaining and predicting motion, loads and structures.
It can be measure it, with force gauges and load cells; calculate it, with Newton laws; resolve and combine forces, as vectors; design against it, in engineering.
Distinguishing features
A vector: magnitude and direction
Changes motion per Newton second law
Fundamental forces underlie all others
Force in social senses is a different entry
What it looks like
Not visible; seen through its effects on motion and shape.
Physical character
SI unit: newton N - 1 N = 1 kg m/s2
weight of 1 kg on Earth: 9.81 N
How it is recognised
Values in newtons or kilonewtons
Force diagrams with arrows
Named forces such as lift, drag, weight, friction
Related models
is a kind of - vector
changes - dynamics
is related to - work = force x distance
is confused with - homonyms
In practice
Families and kinds
gravitational, electromagnetic, strong and weak nuclear forces
contact forces: friction, normal, tension
aerodynamic forces: lift, drag, ground effect
chemical affinity and intermolecular forces
Identifiers
SI unit symbol N newton
Standards and regulation
SI Brochure
Structural design codes specifying loads
ISO 376 calibration of force-proving instruments
Failure modes and hazards
Structural overload
Unit confusion such as kgf and N
Ignoring direction
Analytical facets
- substance
- energy
- origin
- natural
- agency
- inert
- mobility
- not-applicable
- scale
- not-applicable
- affordances
- observable
Also called
+28
Where this came from
oewn:2024 · CC BY 4.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Quantity Magnitude and direction.
Forces are vectors.
Magnitude
Size in newtons.
Magnitude
Magnitude and unit.
- How large is the force, in newtons? measurement
- How was it measured or calculated? provenance
Direction
Line of action.
Direction
Direction and point of application.
- In what direction does it act, and where? definition
- Is it constant or varying? measurement
Kind Which force.
Kind decides behaviour.
Type
Gravity, friction, lift.
Type
Type of force.
- What kind of force is it? definition
- What causes it? definition
Model
Governing law.
Model
Governing equation.
- Which law or model describes it? definition
- Under what conditions is it valid? boundary
Effects Motion and deformation.
Effects are what engineers design for.
Motion
Acceleration.
Motion
Effect on motion.
- What acceleration does it produce? measurement
- What other forces act? definition
Deformation
Stress and strain.
Deformation
Effect on structures.
- What stress does it cause in the structure? measurement
- Is it within limits? boundary
Safety Loads and margins.
Force errors break things.
Loads
Design loads.
Design load
Design loads and factors.
- Which design load and safety factor apply? provenance
- Could dynamic effects exceed them? boundary
Units
Consistency.
Units
Unit consistency.
- Are units consistent, avoiding kgf and lbf confusion? boundary
- Has the calculation been checked? action
What the second pass must settle
- Should fundamental forces be separate entries?
- How should named engineering forces be linked?
- The registry entry has merged aliases such as lift; should they be split off?