| Body force: | (english) An external force acting throughout the mass of a body. Gravity is a body force. An inertial force is a body force. |
| Center of Gravity (CG): | (english) The location of the resultant of gravity forces on an object or objects: sometimes called center of mass. |
| Concentrated force: | (english) A force considered to act along a single line in space. Concentrated forces are useful mathematical idealizations, but cannot be found in the real world, where all forces are either body forces acting over a volume or surface forces acting over an area. |
| Connection: | (english) Connection is similar to the concept of support, except that connection refers to a relationship between members in a structural model. A connection restrains degrees of freedom of one member with respect to another. For each restrained degree of freedom, there is a corresponding force transferred from one member to the other; forces associated with unrestrained degrees of freedom are zero. See fixed connection and pin connection. |
| Couple: | (english) A system of forces composed of two equal forces of opposite direction, offset by a distance. A couple is statically equivalent to a moment whose magnitude equals the magnitude of the force times the offset distance. |
| Distributed load: | (english) An external force which acts over a region of length, surface, or area: essentially any external force which is not a concentrated force. |
| Dynamic equilibrium: | (english) Equilibrium which includes inertial forces. |
| Energy: | (english) A property of a body related to its ability to move a force through a distance opposite the force's direction; energy is the product of the magnitude of the force times the distance. Energy may take several forms: see kinetic energy, potential energy, and elastic energy. |
| Equilibrium: | (english) An object is in equilibrium if the resultant of the system of forces acting on it has zero magnitude. See static equilibrium and dynamic equilibrium. |
| External force: | (english) A surface force or body force acting on an object. External forces are sometimes called applied forces. |