初二物理“大气的压强”一节,空气有重量的演示实验,不容易取得显著的实验效果.因此,我对这个实验作了如下改进. 考虑足够大的容器,不超过天平量程和抽气方便可靠,我改用一只排球作容器.胶皮排球直径20厘米,内径19.6厘米,容积3940厘米~3,用打气筒和球针代替抽气机。用球针放出球内空气,挤压球壳,尽量排出球内 The second day of Physics “atmospheric pressure ” section, air demonstration experiment with weight, is not easy to obtain significant experimental results. Therefore, I made the following improvements to this experiment. Consider a large enough container, not more than the balance scale and Easy and reliable pumping, I use a volleyball as a container. Rubber volleyball diameter 20 cm, diameter 19.6 cm, volume 3940 cm ~ 3, with a pump and ball needle instead of suction. Use the ball needle to release the air inside the ball, squeeze the ball shell, discharge the ball as much as possible