A comment on equilibrium of theoretical mechanics
Chunxiang Wang · Journal of Harbin University of Commerce · 2010
In statics,if the principal vector and principal moment of external force are zero,the general force system is equillibrium.In dynamics,according to the theorem of momentum and the theorem of moment of momentum,the fact that the principal vector and principal moment of external force are zero is called the conservation of momentum and the conservation of moment of momentum.In the method of kineto-statics,if the principal vector and principal moment of the inertia force system are zero,the principal vector and principal moment of the external forces are zero,or in other word,system is at equillibrium.In those three cases,the principal vector and principal moment of the external force system are all zero.However,the terminology is different,which causes some controversion.Most theoretical mechanics textbooks give the definition of equillibrium in the beginning.This definition,however,is controversial.This paper focuses on the conflict of this definition,points out the problem and proposes some possible solutions.