《反冲》一课要求学生认识反冲现象及其应用,教材中设计的实验是用一个塑料瓶,将瓶口部分截掉,在瓶壁下部沿一个方向斜扎六个等距离的小孔,用细线悬挂,瓶内注满水后,瓶子开始向喷水的相反方向旋转,学生可以观察到瓶子产生的反冲现象。这个实验形象直观,制作简便,效果也不错。但 The lesson “Recoil” requires students to understand the recoil phenomenon and its application. The experiment designed in the textbook uses a plastic bottle to cut off the mouth of the bottle, and slants six holes at equal distances along the bottom of the bottle wall in one direction. After suspending with a thin line, the bottle is filled with water and the bottle starts to rotate in the opposite direction to the water spray. Students can observe the backlash generated by the bottle. This experimental image is intuitive, easy to make and effective. but