满分5 >
初中物理试题 >
把篮球抛向空中,忽略空气阻力,哪一图象能正确反映球离手后至落回地面前机械能(E ...
把篮球抛向空中,忽略空气阻力,哪一图象能正确反映球离手后至落回地面前机械能(E )与篮球离地面高度(h )的关系( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980006_ST/images0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980006_ST/images1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980006_ST/images2.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980006_ST/images3.png)
考点分析:
相关试题推荐
密封的烧瓶中装有某种气体,如图所示,图中的黑点表示气体分子,用抽气筒抽出该烧瓶中部分气体后仍密封,描述烧瓶内剩余气体分子的四个示意图如图所示,其中正确的是( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980005_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980005_ST/images1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980005_ST/images2.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980005_ST/images3.png)
D.
查看答案
如图所示,有一斜面长为L,高为h,现用力F沿斜面把物重为G的物体从底端匀速拉到顶端.已知物体受到斜面的摩擦力为f,则下列关于斜面机械效率η的表达式正确的是( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980004_ST/images0.png)
A.η=
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980004_ST/0.png)
×100%
B.η=
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980004_ST/1.png)
×100%
C.η=
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980004_ST/2.png)
×100%
D.η=
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980004_ST/3.png)
×100%
查看答案
下列关于力的说法中,正确的是( )
A.物体在平衡力的作用下机械能保持不变
B.如果两个力大小相同,方向相反,这两个力一定是平衡力
C.物体运动状态改变时,一定受到力的作用
D.物体在平衡力的作用下一定保持匀速直线运动
查看答案
如图所示的事例中,属于增大压强的是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980002_ST/images0.png)
书包背带做得较宽
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980002_ST/images1.png)
切苹果器的刀片做得较薄
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980002_ST/images2.png)
铁轨铺在枕木上
D.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980002_ST/images3.png)
“好奇”号火星车模型轮子大而宽
查看答案
如图所使用的杠杆属于费力杠杆的是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980001_ST/images0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980001_ST/images1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZWL/web/STSource/20131028160558435798099/SYS201310281605584357980001_ST/images2.png)
D.
查看答案