Columns of water in inverted containers, such as upside-down glasses of water, are classic phenomena that demonstrate the effects of atmospheric pressure. This paper presents an analytical method to explore the role of liquid bridges and the associated capillary forces in the equilibrium condition and the criticality of water columns held in inverted containers by a cover sheet. This method has been validated by comparing with experimental data and previous methods. Furthermore, we found that the cover sheet was not separated from the water column, but instead fell together with it, during the drop. The analytical calculation shows that the water is prone to flow out with the glass half full of water, and the cover sheet is prone to attach to a wider or a shorter glass. Furthermore, we found the conditions for pressure balance of the cover sheet and of the water column are different. The cover sheet does not fall down due to differences in pressure between the upper and lower su...

中文翻译：

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倒置水柱中的临界度预测

倒置容器中的水柱（例如倒置的水杯）是经典现象，证明了大气压的影响。本文提出了一种分析方法，以探讨液桥的作用以及相关的毛细管力在平衡条件下的作用以及盖在倒置容器中的水柱的临界度。通过与实验数据和以前的方法进行比较，已经验证了该方法。此外，我们发现盖板在掉落过程中并未与水柱分离，而是与水柱一起掉落。分析计算表明，水容易流到一半充满水的玻璃上，而盖板容易附着在更宽或更短的玻璃上。此外，我们发现盖板和水柱的压力平衡条件不同。盖板不会由于上下电源之间的压力差而掉落。