功率是机械能一章中的重要概念。教学中发现,有许多同学在处理瞬时功率特别是有关瞬时功率最大值的分析和计算时,经常会感到束手无策、力不从心。下面通过高三物理复习中遇到的一道选择题,来谈谈瞬时功率最大值的几种典型求法,以期起到对功率复习时的抛砖引玉作用。例题、一可视为质点的小球用一不可伸长的轻绳悬挂于某固定点O,如图1所示,现将轻绳拉直, Power is an important concept in the chapter Mechanical Energy. Teaching found that many students in the processing of instantaneous power, especially the maximum instantaneous power analysis and calculation, often feel helpless, unable to do anything. The following through the third year physics review encountered a multiple-choice questions, to talk about the instantaneous maximum power of several typical methods, in order to play a power review of the role of initiator. Example, a particle can be regarded as a particle with a non-elongated light rope hanging at a fixed point O, as shown in Figure 1, now the light rope straightened,