“功”是高中物理中重要知识点,在“教学大纲”中,它属于B级内容。“大纲”对B级内容的要求是:理解知识的确切含义以及与其它知识的联系,并能在对实际问题进行分析、综合和判断等过程中运用它们。以下几个例题,对理解功的含义,提高学生综合运用的能力,有一定的启发作用。 例1 如图1所示劈α放在光滑水平桌面上,其斜面也光滑。把b物放在α的斜面顶端由静止下滑,则b从顶端滑到底端的过程中,α作用在b上的弹力对b作功的情况是: “Power” is an important knowledge point in high school physics, in the “syllabus”, it belongs to Class B content. The requirements of Category B content are: understanding the exact meaning of knowledge and its links with other knowledge, and applying them to the analysis, synthesis and judgment of practical problems. The following few examples, to understand the meaning of work, improve the ability of students to use comprehensively, there is a certain enlightenment. Example 1 As shown in Figure 1 split α on a smooth horizontal desktop, the bevel is also smooth. The b object on the top of the bevel α slip down from the static, then b from the top to the bottom of the process of sliding, α acting on the b on the elastic work on b is: