कौन सा प्रमेय या सिद्धांत यह बताता है कि किसी प्रणाली पर कार्य करने वाले शुद्ध बाहरी बल और परिणामी विपरीत प्रभावी बल (जड़त्व बल) संतुलन में होते हैं?

In standard assumptions made for plane truss structures, the connections between members are assumed to be joined by:

The coefficient of friction is theoretical value of _____ for ideal, perfectly smooth surfaces.

In the analysis of structures by the principle of Virtual Work, which of the following forces are assumed to do work and are not omitted?