Barycentre

From Citizendium
Revision as of 16:08, 26 November 2008 by imported>Richard Pinch (New entry, just a stub)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

In geometry and physics, the barycentre or centre of mass or centre of gravity of a system of particles or a rigid body is a point at which various systems of force may be deemed to act. The gravitational attraction of a mass is centred at its barycentre (hence the term "centre of gravity"), and the (classical) angular momentum of the mass resolves into components related to the rotation of the body about its barycentre and the angular movement of the barycentre.

The barycentre is located as an "average" of the masses involved. For a system of n point particles of mass located at position vectors , the barycentre is defined by

For a solid body B with mass density at position , with total mass

the barycentre is given by