我针对“运动的合成和分解”教学演示实验中的不足之处,进行了如下改进:1.为方便控制红蜡块 R 何时开始上浮,以确定计时开始时刻,可在原实验的基础上做如下改进:如图1所示,在红蜡块的外面捆一两圈细铁丝,并准备一块小磁铁,当磁铁从玻璃管外面接触红蜡块上 In order to facilitate the control of when the red wax block R began to float to determine the starting time of timing, the basis for the original experiment was based on the following deficiencies in my teaching demonstration of “composition and decomposition of sports”. The following improvements are made: As shown in Fig. 1, two thin wires of iron are bundled outside the block of red wax, and a small magnet is prepared. When the magnet contacts the block of red wax from outside the glass tube