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刘卓同志在《江苏教育》1982年8期《介绍一个力学实验》中指出:“用手指将木块(底部镶有玻璃板)一直压到缸底后再抽去手指,木块就再也浮不上来了。”并说明,这时木块与缸底之间的水已被排开,没有水,也就谈不上木块底部的水对木块有任何向上的压力,也就不存在上下压力差,当然物体也就没有受到水对它的浮力了。这在理论上是正确的,但就实验来说还有其不足之处。木块压入水缸底后,镶在木块上的玻璃板与水缸底部玻璃之间的水会被排开,但毕竟不可能全部、彻底地被排开,实际操作中总还有一些水的存在,因此这个实验不易做好。现在有这样一个装置,可以避免以上不足之处,提出来供大家参考。
Comrade Liu Zhuo pointed out in his book “Introducing a Mechanical Experiment” in “1982 Jiangsu Education” (1982): “Pressing a piece of wood (with a glass plate on the bottom) Floating up. ”And that, when the water between the block and the bottom of the cylinder has been lined up, there is no water, it does not mention the water at the bottom of the wooden blocks have any upward pressure on the wood, it will not There is pressure difference between the upper and lower, of course, the object is not subject to the buoyancy of water on it. This is theoretically correct, but there are still some deficiencies in terms of experimentation. After the wooden block is pressed into the bottom of the water tank, the water between the glass plate mounted on the wooden block and the glass in the bottom of the water tank will be discharged, but after all, it is impossible to be completely and completely drained, and there is always some water in actual operation The existence of this experiment is not easy to do well. Now there is such a device, to avoid the above deficiencies, put forward for your reference.