初中物理中的液面升降问题,常有考题出现,这类题通常根据阿基米德原理和物体的浮沉规律来判断。其中有一种特殊题型部分同学在解答中常出错。现举例说明供大家参考。如图:一冰块漂浮在盐水中,则水熔化后,液面将()A.升高B.不变C.降低D.无法判断分析(方法一)∵ρ冰<ρ水<ρ盐水∴冰、水在盐水中均是漂浮∴冰未熔化前受到的浮力为:F浮= In the physics of junior high school, the problem of liquid level rise and fall often arises. Such questions are usually judged according to Archimedes’ principle and the floating law of objects. One of the students with a special type of questions often made mistakes in their answers. Here is an example for your reference. As shown in the figure: If a piece of ice floats in salt water, the water will melt, the liquid surface will () A. rise B. unchanged C. decrease D. can not be judged (method 1) ∵ρ ice <ρ water <ρ brine The ice and water in the salt water are floating. The buoyancy before the ice is not melted is: F float =