Originally Posted by
Joe Leppo
No, it's not...we are concerned with the Forces / Torque / Moments present during an instant in time, which is what the diagram is illustrating.
Kinematics: the branch of mechanics concerned with the motion of objects without reference to the forces which cause the motion.
Statics: the branch of mechanics that is concerned with the analysis of loads (force and torque, or "moment") acting on physical systems that do not experience an acceleration (a=0), but rather, are in static equilibrium with their environment.
Dynamics: the branch of mechanics concerned with the study of forces and their effects on motion. (a does not = 0)
You might find this hard to believe, but a number of us SSCs have backgrounds in Engineering or Physics. This material has been scrubbed, discussed, argued over, etc.