如图所示,A、B两球质量均为m,之间有压缩的轻短弹簧处于锁定状态.弹簧的长度、两

题型:问答题

问题:

如图所示,A、B两球质量均为m,之间有压缩的轻短弹簧处于锁定状态.弹簧的长度、两球的大小均忽略,整体视为质点,该装置从半径为R的竖直光滑圆轨道左侧与圆心等高处由静止下滑,滑至最低点时,解除对弹簧的锁定状态之后,B球恰好能到达轨道最高点.

(1)求弹簧处于锁定状态时的弹性势能.

(2)求A上升的最大高度.(答案可以保留根号)

考点:动量守恒定律
题型:问答题
附加题:(卷面成绩已达到60分以上的,本题不加分;达不到60分的,做对的可加分,但总分不超过60分)
(1)分式
1
x
有意义的条件是______;
(2)直角三角形的两直角边为3、4,斜边长为______.
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小题2:Although the sound system caused a few problems, the ________ could still enjoy the concert.

小题3:I was ready to ________ paper cutting for myself. Mr Chen could help me make my first paper cut.

小题4:Its black eyes, which _____________ the cabbage, show the creature’s interest in the vegetable.

小题5:His soft portraits of beautiful women are very ___________.

小题6:Paper cuts of animals have been found in tombs which ___________to the time of the Northern and Southern Dynasty.

小题7:Paper cuts used for _____________ purposes are often found in temples.

小题8:______________ the old stories of Iceland and Norway, Eric the Red was forced to leave Iceland.

小题9:Eric the Red had ____________ a murder, for which he got into trouble.

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题型:问答题

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A.接种后局部反应

B.接种后全身反应

C.接种后过敏反应

D.接种后局部中等反应

E.接种后局部强反应

题型:问答题

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A.劳动报酬所得

B.稿酬所得

C.保险赔款

D. * * 中彩所得

题型:问答题

研究者须经三个步骤完成问卷,下列哪个步骤不正确( )。

A.设计问卷初稿

B.试用和修改

C.进行探索性工作

D.形成开放式问卷

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