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一、连续媒质的流动问题例1.如图1所示,一个粗细均匀的U形管内装有同种液体,并竖直放置。右管口用盖板A密闭,左管口不封闭。左、右管内两液面的高度差为h,U形管中液柱总长为4h。现拿去盖板,液柱开始流动。当管内两液面的高度恰好齐平时,右侧液面下降的速度是多少?解析:将盖板A拿去后,右管液面下降,左管液面上升,管内的重力势能减少,动能增加。当左、右两管液面相平时,势能最小,动能最大。设液体密度为ρ,液柱的截面积为S,液柱流动的最大速度为V。
First, the flow of continuous media problems Example 1. As shown in Figure 1, a uniform thickness U-shaped tube containing the same liquid, and placed vertically. The right orifice is covered with a flat cover A, the left orifice is not closed. Left and right tube two liquid surface height difference h, U-shaped tube in the total length of liquid column 4h. Now take cover, liquid column began to flow. When the two liquid level in the pipe just flush, the right side of the liquid level is how much? Analysis: After removing the cover A, the right tube surface decreased, the left tube surface, the tube potential energy reduction, kinetic energy increase. When the left and right two tube surface level when the potential energy minimum, maximum kinetic energy. Suppose the liquid density is ρ, the liquid column’s cross-sectional area is S, and the maximum velocity of liquid column flow is V.