The three fundamental laws governing classical mechanics.
Newton's three laws that describe the relationship between a body and the forces acting upon it.
An object at rest remains at rest, and an object in motion continues in motion at constant velocity, unless acted upon by a net external force.
The net force on an object equals the rate of change of its momentum:
For variable mass systems (e.g. rockets), the full form is .
For every action there is an equal and opposite reaction:
See also: article-general-relativity for the relativistic extension.
The Newtonian causal chain is visualised in object-newtonian-flow.