一个小球在竖直环内至少做N次圆周运动，当它第（N-2）次经过环的最低点时的速度是

发布时间：2017-06-02 09:27 │ 来源：www.tikuol.com

题型：选择题

问题：

一个小球在竖直环内至少做N次圆周运动，当它第（N-2）次经过环的最低点时的速度是7m/s；第（N-1）次经过环的最低点时的速度是5m/s，则小球在第N次经过环的最低点时的速度v一定满足（　　）

A．v＞1m/s

B．v=1m/s

C．v＜1m/s

D．前面三种情况都有可能

考点：向心力牛顿第二定律动能定理

题型：选择题

任务型阅读。

Co-operation (合作) is always needed when you make a project that the teacher gives you.
First, discuss all you would like to do with your classmates. Choose one of the members to write down
what you're talking about. Then, with the ideas you get, list all you want. Everyone shares the duty for the
project. You can collect information not only from books but also on the Internet. Making a survey and doing
a research are also good ways. After that, all the members put what has been found together. Try to make
the project more well-organized. In the end, you can give a report in front of your class to show the results
of your hard work.

根据短文内容，填写下列表格。

You need 1__________ when you make a project.

★First, 2___________ with your classmates and choose one member to
    3__________ what you're talking about.
★Second, collect and list all you want and 4__________ and
    are also good ways.
★After that, put what has been found together and make the project more
    well-organized.
★In the end, show the results of your hard work by 5___________.

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题型：选择题

石膏综合征常发生于（）

A.糖尿病患者

B.石膏背心固定者

C.长腿石膏托固定者

D.缺乏患肢功能锻炼者

E.石膏内有伤口感染者

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题型：选择题

在两类危险源中，第一类危险源控制的方法有( )。

A．增加设备安全系数、提高可靠性

B．消除危险源、限制危险物质

C．进行故障一安全设计

D．设置安全监控系统

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题型：选择题

紧的财政政策与松的货币政策搭配指的是（）

A.扩大财政赤字和收紧信贷规模

B.减少财政赤字和收紧信贷规模

C.扩大财政赤字和扩张信贷规模

D.减少财政赤字和扩张信贷规模

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题型：选择题

对于地势陡峻的断面可采用经纬仪测量，测算数据包括（）。

A.量仪器高

B.测尺读数

C.算竖直角

D.算水平距离和高程

E.丈量距离

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