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山东科技版(司南版)课标实验教材《物理选修3—3》第62面作业第2题,题目如下:题2 图1所示为输液装置的一部分.在输液过程中,瓶中 A 处气体的压强随液面的下降,将怎样变化?B 处药液的下降速度是否变化?为什么?配套《教师教学用书》给出的参考答案如下:随着液面的下降,A 处气体的体积将增大,根据玻意耳定律,在温度不变的条件下,其压强将减小.因此,B 处药液的下降速度将减小.问题显然,《教师教学用书》中的解答存在明显错误.因为输液瓶中不断有空气通过进气管进入,气体质量在不断增加,而解答中根据玻意耳定律,忽视了该定律的适用条件,对一定质量的气体.所以得出错误结论.况且,凡有过输液经历的人都知道输液过程中药液是匀速滴注的.一、“吊针瓶”的药液为何匀速滴注一般人认为是因为“吊针”上的调节器控制的结果,这是错误的,调节器作用类似水池底部有一水龙头,而随着水位下降,水龙头中水流速度逐渐减慢,水龙头只能控制水流的大小
Shandong Provincial Science and Technology Edition (Dean Edition) course teaching experiment textbook “Physical Electives 3-4” on the 62nd surface of the second question, the title is as follows: Question 2 Figure 1 shows part of the infusion device. In the infusion process, the bottle A How does the pressure of the gas change with the liquid level? Will the rate of fall of the liquid at the B be changed? Why? The reference answers given in the “Teacher’s Manual” are as follows: With the decrease of the liquid level, the volume of gas at the A Will increase, according to Boyle’s law, under the condition of constant temperature, the pressure will decrease. Therefore, the speed of the liquid at B will decrease. The problem is obvious, the answer in the “teacher’s book” is obvious Mistakes. Because there is continuous air in the infusion bottle entering through the intake pipe, the gas quality is increasing, and according to Boyle’s law, the solution ignores the applicable conditions of the law and the gas of a certain quality. Therefore, it draws an erroneous conclusion. Anyone who has had experience in infusion knows that the infusion process is instilled in a uniform rate. First, why do the “bottle bottle” liquids instill uniform? Most people think that it is because of the adjustment on the “dumplings”. The result of the controller control, which is wrong, the regulator acts like water There is a faucet at the bottom of the pool, and as the water level drops, the water flow in the faucet gradually slows down. The faucet can only control the size of the water flow.