毛钱管又名牛顿管，在高中物理中用它来演示“自由落体运动”。在使用中，一要小心操作，防止碰撞；二是实验完毕，要拔掉连接毛钱管与抽气机的橡皮管，防止抽气机内的机油倒流。我校一位新老师，对毛钱管不太熟悉，做完实验后没有将橡皮管拔掉，也未将抽气嘴的蝶形阀关闭（不 The dime tube, also known as the Newtonian tube, is used in high school physics to demonstrate “free fall motion.” In use, one must be careful to prevent collisions. Second, after the experiment is finished, remove the rubber tubing that connects the dip tube and the air pump to prevent backflow of the oil in the air pump. A new teacher from our school is not familiar with the cashier tube. After the experiment was done, the rubber tube was not pulled out and the butterfly valve of the suction nozzle was not closed.