现行中师物理课本第二册(以下简称课本)在《液体的表面现象》一节中,不仅定性地介绍了液体的表面现象。而且用实验的方法定量讨论了液体表面张力的大小。然而,如果按照课本上介绍的方法,用弹簧测力计去测量表面张力的大小就很难得到预想的结果,原因是:(1)实验中要测的表面张力一般为零点几克力,所 The second volume of the current physics textbook for middle school students (hereinafter referred to as textbooks) not only qualitatively describes the surface phenomena of liquids in the section “Surface phenomena of liquids”. Moreover, the surface tension of the liquid was quantitatively discussed using experimental methods. However, if the surface tension is measured with a spring dynamometer according to the method described in the textbook, it is difficult to get the expected results because: (1) The surface tension to be measured in the experiment is generally a few grams of force.