通过高中物理竞赛辅导,学生知道了电容为C的电容器充电到两极板间的电压为U时所贮藏的电能为E_电=1/2CU~2。课后学生提出了这样一个问题:如图1所示电路,合上开关S,一个电动势为ε、内电阻可以忽略不计的电 Through the high school physics competition coaching, students know that when the capacitor with capacitor C is charged to the voltage between two plates is U, the stored energy is E_electricity = 1/2CU~2. After class, the students raised the question: As shown in the circuit of Figure 1, close the switch S, an electromotive force is ε, the internal resistance can be ignored