Fr.: équilibre hydrostatique
1) The physical situation reached in a fluid when complete balance exists between
the internal pressure at any point and the weight of the material above the point.
Fr.: équilibre statique
The state of a rigid body which is not moving at all. The conditions for static equilibrium are: 1) the sum of the external forces on the object must equal zero, and 2) the sum of the → torques must equal zero. See also → dynamic equilibrium and → mechanical equilibrium.