第九章 浮力与升力综合能力探究演练(时间45分钟满分100分)一选择题(每题3分共30分)1.(2008·遂宁)我国沉船打捞人员在南海打捞宋朝的商船潜水员在水面下作业当他继续下潜的过程中以下说法正确的是( ) A.所受浮力变大压强变大 B.所受浮力变大压强变小 C.所受浮力不变压强变大 D.所受浮力不变压强不变2.(2007·大连)在公园平静
升力与浮力气体的升力与浮力相同之处:都是物体表面的压力差但是这压力差的产生机制不一样升力产生需要流动着的气体飞机升力:根据能量守恒流速大的气体压强小于流速小的气体压强飞机机翼上表面较弯曲下表面较平直人为使流过上表面的气流流速大于下表面于是产生了压力差这就是飞机的升力由于机翼方向是可变的所以飞机的升力不是总向上风筝升力:吹向风筝的风被风筝阻挡突然减速造成风筝的迎风面的气体压力骤然增大而风筝背面
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Review of Units 5-6责编:郭素清【巩固练习】I 单项选择。(15分,每题1分)1 The Browns usually drive to the park on Sundays But today they go to the park _____ A on feetB on foot C by foot D on the foot2 Bob often _____ his
Unit 4 Amazing science综合能力演练责编:王晓丽【巩固练习】I 单项选择。1 _____ the morning of March 31, she made an important decision in her lifeA Since B InC From D On 2 You’ve saved a lot of money How do you plan to _
Review of Unit 1-2综合能力演练责编:王晓丽【巩固练习】I 单项选择。 (每小题1分,共15分)1 When the player finished running, he was out of _____A breatheB breathingC breathD the breath2Lily, _____ you _____ your ticketNot yet!A did
阿基米德实验.swf 例2 质量是200g的瓶子盛满水后的质量是1.2kg若用这个瓶子盛满某种液体液体和瓶子的总质量是求这种液体的密度并确定它是何种液体60
浮力与升力(二)一一周内容概述1掌握物体沉浮条件 2掌握关于物体沉浮现象的题目的解决方法3掌握浮力综合题的处理方法二重难点知识讲解 (一)流速与压强 1流体压强与流速的关系: 将水平管子右端开口用塞子封住然后向容器R灌水到达一定高度后停止灌水.容器R及三个细管中的液面停在同一高度上在同一水平面上ABC诸点处压强都相等这时的压强是流体在静止时的压强 如果将水平管子D端的塞子拔去同时向容器
Review of Unit 5-6综合能力演练 责编:王晓丽I 单项选择。 (每小题1分,共15分)1 Is that allYes That’s all ______ I want to takeA whichB thatC whoD whose2 Today there are two new students in our class I don’t know ______ of th
Review of Unit 3-4综合能力演练 责编:王晓丽【巩固练习】I 单项选择。 (每小题1分,共15分)1 Hello! May I speak to Alice Sorry, she _____ Shanghai A have gone to B has been toC has been inD has gone to2 The shoes were worn out, wha
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