Conservation of momentum

From Citizendium
Revision as of 21:43, 9 October 2021 by imported>Mark Widmer (Added remarks about external forces.)
Jump to navigation Jump to search
This article is a stub and thus not approved.
Main Article
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
This editable Main Article is under development and subject to a disclaimer.

Momentum is always conserved. The momenta of individual objects in a system may vary, but, in the absence of any external forces, the vector sum of all the momenta will not change. Therefore, momentum is said to be conserved.

If an external force -- that is, a force exerted by an object outside the system -- is exerted on any objects within the system, then the total momentum will change.

The conservation of momentum in a glancing collision between two objects is expressed as

The conservation of momentum in a collision between two objects where the two objects become one is expressed as