大学物理 ›› 2017, Vol. 36 ›› Issue (2): 5-7.doi: 10.16854 /j.cnki.1000-0712.2017.02.002

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虚位移之“虚”表现何在?

刘天贵,刘全慧   

  1. 湖南大学物理与微电子科学学院理论物理研究所,湖南长沙410082
  • 收稿日期:2016-03-10 修回日期:2016-05-20 出版日期:2017-02-20 发布日期:2017-02-20
  • 作者简介:刘天贵( 1973—) ,女,湖南岳阳人,湖南大学讲师,博士.
  • 基金资助:
    国家自然科学基金资助课题( 11175063) ; 湖南大学教改基金资助课题资助

What does“virtual”mean in the virtual displacement?

LIU Tian-gui,LIU Quan-hui   

  1. School for Theoretical Physics,School of Physics and Electronics,Hunan University,Changsha,Hunan 410082,China
  • Received:2016-03-10 Revised:2016-05-20 Online:2017-02-20 Published:2017-02-20

摘要: 阐述使用虚位移处理具体问题可以分解为三步: 1) 对一个具体的物理问题,给出自变量虚位移的定义; 2) 对这个问题需要的函数,由于自变量的虚位移产生的变化; 3) 对相关函数加上物理要求.经过这三步之后,才能给出物理上合理的结果.而其中的第二步,体现了其非真实性.

关键词: 分析力学, 虚位移, 热力学

Abstract: Virtual displacement is an important physical concept in physics.For exaggerating the role of the non-reality in applications of the virtual displacement,we analyze how the virtual displacement is applied,which can be divided into three steps: 1) for a given physical problem,the definition of virtual displacement of a variable is introduced; 2) the variation of a mathematical function along the change of the virtual displacement is given,which is not necessarily compatible with physics principles; 3) with imposing physical conditions on the mathematical function,the physics consequence is resulted.

Key words: analytical mechanics, virtual displacement, thermodynamics