九年级(上)物理9《大气压_气体压强与流速的关系》（Ninth grade (upper) physics 9 relationship between atmospheric pressure and velocity）.doc

九年级(上)物理9《大气压_气体压强与流速的关系》（Ninth grade (upper) physics 9 relationship between atmospheric pressure and velocity） The relationship between atmospheric pressure and gas pressure and flow rate is the teacher: xu fenglin 1. Proof and interpretation of pressure in the atmosphere; 2. Determination of atmospheric pressure and influencing factors; 3. The laws and applications of gas pressure with velocity change. (1) atmospheric pressure 1. The air around the earth is referred to as the atmosphere. The pressure in the atmosphere is called atmospheric pressure, or atmospheric pressure. (1) the mardeburg hemisphere experiment strongly demonstrates the presence of atmospheric pressure. (please refer to annex 01. BMP.) As shown in FIG. 1, the madeburg hemisphere experiment. In the square in the German city of madeburg, there was a famous mardeburg hemisphere experiment in 1654. Combine the two halves of the copper hollow hemispheres of about 0.2 m and pull out the air inside, pulling the two hemispheres in the opposite direction with two horses, hardly able to pull apart. See figure 2 [pic00000. BMP] (please refer to annex 01. BMP.) (2) the following three conditions are related to atmospheric pressure: the plastic hook is attached to a smooth wall, which can withstand a certain tension and not fall off. When sipping a drink through a straw, atmospheric pressure causes the drink to rise to the mouth. Put some water in the iron bucket, close the mouth after boiling, and pour cold water on it. [pic00001. BMP] [pic00002. BMP] [pic00003. BMP] The atmospheric pressure (1) torricellis experiment: the torricelli experiment was one of the first experiments to measure atmospheric pressure. The experiment measured atmospheric pressure at a height of 760mm of mercury. [pic00004. BMP] [pic00005. BMP] [pic00006. BMP] [pic00007. BMP] (2) influence of atmospheric pressure: height. The atmospheric pressure decreases with the increase of height, and within 3000m above sea level, approximately 10