在力学中对研究对象进行能量分析,涉及重力势能和动能的确定,以及它们之间的相互转换,学生容易适应.但在电场中,除具备上述的分析内容外,还有带电体的电势能以及电场力对电荷做功而引起带电体本身电势能的改变的问题.使得学生感到电场中的能量分析头绪多、问题复杂、而且容易出错. The energy analysis of the research object in mechanics involves the determination of the gravitational potential energy and kinetic energy, as well as the mutual transformation between them. The students are easy to adapt. But in the electric field, in addition to the above analysis content, there is the potential energy of the charged body. And the problem that the electric force exerts power on the charge and causes the change of the potential energy of the charged body. This makes the students feel that the energy analysis in the electric field is complicated, the problem is complex, and it is prone to error.