The reason why the law of mechanical energy can not be satisfy the principle of relativity is the definition of externalpotentialenergy; and it is analyzed.
分析了机械能定理不满足力学相对性原理的原因在于外势能的定义，提出了对势能定义的看法。
2
Total potentialenergy is composed of elastic and dissipated potential energies in shear band as well as work done by external force.
系统的总势能由剪切带的弹性及耗散势能和带外弹性岩石对剪切带所作的外力功构成。
3
By introducing the concept of impulse potentialenergy, the generalized impulse-momentum equation is developed which describes the dynamics of a flexible robot with external impacts.