问题 填空题

如图所示,将一个重30 N、体积为0.002 m3、用绳子悬挂着的物体浸没在烧杯里的水中,物体受到的浮力是_____ N(g取10N/kg)。物体浸入水后,水对杯底的压强   (填“增大”、“不变”或“减小”)。释放绳子后,物体将        

答案

20;增大;下沉.

题目分析:(1)当物体浸没于水中时,V=V=0.002m3

物体所受的浮力为:

(2)物体浸入水后,烧杯内水深h增大,由公式p=ρgh可知水对杯底的压强增大;

(3)∵当物体浸没在水中,G=30N,F=20N,∴F<G,∴释放绳子后,物体将下沉.

阅读理解

阅读短文,回答问题。

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单项选择题 A1/A2型题