问题 计算题

【物理——选修3-5】(15分)

小题1:下列说方法正确的是        (   )

A.人类关于原子核内部的信息,最早来自天然放射现象

B.在α、β、γ三种射线中γ射线电离作用最强

C.放射性元素的半衰期会随着温度的升高而缩短

D.较重的核分裂成中等质量大小的核或较轻的核合并成中等质量大小的核,核子的比结合能都会增加小题2:某小组在探究反冲运动时,将质量为m1一个小液化瓶固定在质量为m2的小球具船上,利用液化瓶向外喷射气体做为船的动力。现在整个装置静止放在平静的水面上,已知打开液化汽瓶后向外喷射气体的对地速度为v1,如果在△t的时间内向后喷射的气体的质量为△m,忽略水的阻力,则

(1)喷射出质量为△m的液体后,小船的速度是多少?

(2)喷射出△m液体的过程中,小船所受气体的平均作用力的大小是多少?

答案

小题1:AD

小题2:

得:v=

(2)对喷射出的气体运用动量定理得:Ft=△mv1

解得F= 。

单项选择题
完形填空

 

第三节完型填空(共20小题,每小题1.5分,满分30分)

阅读下面短文,掌握其大意,然后从21—40各题所给的四个选项(A、B、C和D)中,选出一个可以填入空白处的最佳选项,并在答题卡上涂黑。

He lost his arms in an accident that caused the death of his father. Then his   21   became his shadow, never leaving him alone for years.   22  writing with his toes, he was completely unable to do anything in his life.

As the two brothers grew up together, they had their   23   of problems and they would often quarrel. Then one day, his younger brother decided to    24   separate from him, living his own life as many   25  people do. So he was heart-broken and didn’t know what to do.

A   26   misfortune happened to a girl, too. One night she tried to   27  meals for her sick mother, only to overturn the kerosene light on the stove, resulting in a fire which took her 28  away.

Though her elder sister in another city  29  her willingness to take care of her, she was

30   to learn to be completely independent. At school, she   31   studied hard.

One day, the boy and the girl were both invited to   32   on a television interview program and asked to   33  something on a piece of paper with their toes. The boy wrote; My younger brothers arms are my arms;   34   the girl wrote: Broken wings, flying heart.

They had both   35   the same pain, but their different attitudes determined the nature of their lives. It is true that life is unpredictable(难以预料). Disasters can strike at   36   time. If you choose only to complain and   37  , it will always follow you   38   you go. But if you decide to be   39 , the hard moment will   40   to be one when new hopes will arise.

21.A.older sister       B.uncle       C.younger brother   D.mother

22.A.Instead of     B.Except for        C.Thanks to        D.In spite of

23.A.share         B.goal       C.agreement       D.enjoyment

24.A.live          B.tell         C.come           D.learn

25.A.rich          B.normal      C.unlucky         D.disabled

26.A.different      B.strange      C.special         D.similar

27.A.prepare        B.offer       C.have            D.order

28.A.ears          B.toes        C.feet              D.hands

29.A.explained     B.showed      C.pointed         D.discussed

30.A.satisfied       B.excited      C.determined      D.disappointed

31.A.hardly         B.seldom      C.always         D.sometimes

32.A.sing         B.dance            C.turn             D.appear

33.A.say           B.draw       C.write            D.copy

34.A.while              B.when       C.since            D.unless

35.A.hidden         B.suffered     C.discovered       D.overcome

36.A.one          B.no          C.any             D.this

37.A.comfort       B.Discourage  C.watch          D.escape

38.A.whenever     B.wherever   C.if             D.because

39.A.silent         B.noisy       C.weak            D.strong

40.A.turn out       B.bring about  C.come up         D.give off