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一位中学物理教师来访时,谈到78年版初二物理课本在大气压一节中有这样一道习题:“取两个粗细相差很小的试管,在大试管里装满水。把小试管底朝下放到大试管里。把这样装好的两个试管倒过来,就会看到大试管里的水徐徐流出,同时小试管自动上升到大试管里。解释这个现象。”她说:“有的教学参考资料仅把这个现象解释为大气压的作用,但这样的解释嫌笼统。”又说:“如果认为细管的上升是由于大气压力作用在细试管内壁顶端的缘故,那么细管外壁顶端(如图中b点)也受到向下压力的作用,而且,按照帕斯卡定律,作用
When a middle school physics teacher came to visit, he said that the 78th edition of the second day physics textbook had an exercise in the section of atmospheric pressure: “Take two test tubes with very small differences, fill the large test tube with water. Turn the small test tube toward the bottom. Drop it into a large test tube. Turning the two tubes in this way upside down will see the water in the large tube slowly outflow and the small tube automatically rises into the large tube. Explain this phenomenon.“ She said: ”Some The teaching reference material only interprets this phenomenon as the effect of atmospheric pressure, but such an explanation is too general.” added: “If we think that the rise of the thin tube is due to atmospheric pressure acting on the top of the inner wall of the thin test tube, then the top of the thin tube outer wall ( (point b in the figure) is also subjected to downward pressure, and, in accordance with Pascal’s law,