题目内容
两个实心物体.它们质量之比是2:1,体积之比是2:3,则这两物体密度之比是( )A.3:1
B.4:3
C.3:4
D.1:3
【答案】分析:已知他们的质量之比和体积之比,根据公式ρ=
可求密度之比.
解答:解:已知:
=
,
=
,
则密度之比
=
=
×
=
×
=
.
故选A.
点评:本题考查密度的计算,关键是公式及其变形的灵活运用,本题相对比较简单,属于基础题.
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/0.png)
解答:解:已知:
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/1.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/2.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/3.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/4.png)
则密度之比
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/5.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/6.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/7.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/8.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/9.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/10.png)
![](http://thumb.1010pic.com/pic6/res/czwl/web/STSource/20131028160829504596420/SYS201310281608295045964002_DA/11.png)
故选A.
点评:本题考查密度的计算,关键是公式及其变形的灵活运用,本题相对比较简单,属于基础题.
![](http://thumb2018.1010pic.com/images/loading.gif)
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