力的合成遵循平行四边形定则而不符合代数运算法则.如何使刚上高一的学生相信这一点,做好演示实验是关键.课本上关于这个实验是用橡皮条和钩码来完成, 实验过程如图1所示.为便于演示和作图方便,这个实验的分力F_1和 F_2与合力 F 应为整数,如课本插图中 F_1=3,F_2=4,F=5,这样一来,F_1与 F_2间夹角,及F_1、F_2跟 F 的夹角只能是特定的值.要做好演示,课前必须反复实 The synthesis of force follows the parallelogram rule and does not comply with the algebraic algorithm. How to make this freshman student believe it, the demonstration experiment is the key. The textbook on this experiment is done with a rubber band and a hook code. The process is shown in Figure 1. For ease of presentation and graphing, the force components F_1 and F_2 and resultant force F of this experiment should be integers. For example, F_1=3, F_2=4, and F=5 in the textbook illustration. The angle between F_1 and F_2, and the angle between F_1, F_2 and F can only be a specific value. To do a demonstration, you must repeat it before class