论文部分内容阅读
在新编初中物理第一册第122页上,讲到大气压强一节时,介绍了一个用天平称量空气质量的演示实验。我们要问:这个演示实验的原理是什么呢?为什么增加的砝码就等于瓶中空气的质量呢?这正是本实验教学的难点所在。按照教材本身的叙述层次和学生的认识能力,只能作如下的解释:用天平进行两次称量就可以测出瓶中空气的质量。第一次称量时,由于瓶中空气全部
On the 122th page of the first volume of the new junior high school physics book, when it comes to atmospheric pressure, a demonstration experiment using a balance to weigh air mass was introduced. We want to ask: What is the principle of this demonstration experiment? Why does the added weight equal to the quality of the air in the bottle? This is the difficulty of this experimental teaching. According to the narrative level of the teaching material itself and the student’s cognitive ability, only the following explanation can be made: The weight of the air in the bottle can be measured by weighing it twice with a balance. When weighing for the first time, because the air in the bottle is all