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为让学生直观而深刻地感受到大气压力的存在,教学《自然》三册第十五课《大气的压力和浮力》时,我先做了个魔术.课前,我在一只瓷碗(或其他器皿)里盛满清水,养两条小金鱼,另找一块稍大的照相用的废底片,剪成与碗口外径同样大小的圆形,盖在碗口上.再把瓷碗完全倒转过来平放在桌子上.由于大气压力的作用,圆形底片被紧紧地压在碗口上,不会脱落,水和鱼也仍留在
In order to let the students intuitively and profoundly feel the existence of atmospheric pressure, I first made a magic lesson when teaching the 15th volume of “Nature” Volume 15, “Atmospheric Pressure and Buoyancy.” Before class, I was in a porcelain bowl Or other utensils) filled with water, raise two small goldfish, and find a slightly larger piece of photographic waste film, cut into the same diameter with the outer diameter of the bowl mouth, covered in the mouth on the bowl and then completely inverted Come flat on the table. Due to the action of atmospheric pressure, the circular negatives are tightly pressed onto the bowl and will not fall off. Water and fish will still remain