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一、关于大气压强成因的两种观点关于大气压强产生的原因,在辞海和初中物理教材中解释为是由于大气层的重量产生的,但是在现行高中物理与普通物理教材中又认为是由于气体分子对与其接触的物体的碰撞产生的。这两种说法各有其实验基础。初中物理教学中,教师常以托里拆利实验来显示由大气重量产生的压强可以和由76cm左右的汞柱产生的压强相平衡,用以证明大气压是由大气层的重量产生的。而在高中教学中,教师在空杯子口蒙上一层弹性薄膜,由于薄膜呈水平状,说明杯子内外的空气对薄膜的压强是相等的。然而杯中空气柱的重量是绝对不足以产生像76cm汞柱这么大的压强的,这只能使人“相信”杯中的气压是由于空气分子对杯壁的密集的、激烈的碰撞的效应了。
I. Two Views on the Causes of Atmospheric Pressure The causes of atmospheric pressure are explained in the Cihai and junior high school physics textbooks as being due to the weight of the atmosphere, but they are also believed to be due to gas molecules in current textbooks for high school physics and general physics. A collision with an object in contact with it. Both of these arguments have their experimental basis. In junior high school physics teaching, teachers often use Torricelli’s experiment to show that the pressure generated by the atmospheric weight can be balanced with the pressure generated by a mercury column about 76 cm to prove that the atmospheric pressure is generated by the weight of the atmosphere. In high school teaching, the teachers covered an empty layer of elastic film on the empty cup. Because the film is horizontal, it means that the air pressure inside and outside the cup is equal to the film. However, the weight of the air column in the cup is absolutely not enough to produce a pressure as large as 76 cm Hg. This can only make people believe that the pressure in the cup is due to the dense and intense collision of air molecules against the wall of the cup. Effect.