问题 问答题

某同学让重锤做自由落体运动,利用打点计时器打出的纸带来测量当地的重力加速度.该同学在实验中得到6条纸带,如图所示为其中一条,在纸带上取6个计数点,两个相邻计数点间的时间间隔为T=0.02s.其中1、2、3点相邻,4、5、6点相邻,在3点和4点之间还有若干个点.s1是l、3两点的距离,s3是4、6两点的距离,s2是2、5两点的距离.

(1)测sl、s2、s3后,点2速度的表达式v2=______

(2)该同学测得的数据是s1=4.00cm,s2=19.30cm,s3=8.72cm,根据数据求出重力加速度g=______rn/s2(保留三位有效数字).

答案

(1)根据中点时刻的速度等于平均速度得:

v2=

s1
2T

v5=

s3
2T

(2)根据匀加速直线运动位移速度公式可知:

2gs2=v52-v22

代入数据解得:g=9.72m/s2

故答案为:

s1
2T
;9.72

阅读理解

阅读理解。

     Baseball is one of the favorite sports in the U.S.A. Children play baseball in sports fields or parks.

     At summer picnic, there is often an informal baseball game. Boys and girls, young and old take turns

to bat. There are nine players on each team.

     The baseball season goes from April to September. During this time, baseball matches are showed

on TV and members of the important baseball teams become America's heroes(英雄). At the end of the

season the two top teams play against each other. Many baseball fans go along to watch the game.

Millions of others listen to the radio or watch the television. People seem to talk only about the game.

Even long after it is over, they still talk about the result and the players.

     American football is perhaps the most popular sport in the U.S.A. The football season begins when

the baseball season ends. More people are interested in football than baseball. When there is an

important game, thousands of people sit beside radios or in front of television sets to get the result.

1. According to the passage, which is wrong?

A. Boys and girls like baseball games.

B. Baseball is played in the open air.

C. A baseball match has nine players.

D. Children sometimes play baseball in parks.

2. American people play baseball in April, _______ and September.

A. May, June, July, August

B. March, May, July, August

C. January, June, October, November

D. February, May, July, December

3. What happens at the end of the baseball season?

A. People talk only about football games.

B. Many baseball fans become members of top teams.

C. A lot of people join in the games.

D. Two top teams play a wonderful baseball game.

4. _______ follows the baseball season in the U.S.A.

A. The baseball season

B. The football season

C. A baseball match

D. A football match

5. This passage mainly tells us something about _______.

A. the football season in the U.S.A.

B. football is more interesting than baseball in the U.S.A.

C. the difference between baseball and football

D. the baseball season in the U.S.A.

阅读理解与欣赏

阅读下面语段,完成下面问题。

  子曰:“学而时习之,不亦说乎?有朋自远方来,不亦乐乎?人不知而不愠,不亦君子乎?”

  曾子曰:“吾日三省吾身:为人谋而不忠乎?与朋友交而不信乎?传不习乎?

  子曰:“温故而知新,可以为师矣。”

  子曰:“学而不思则罔,思而不学则殆。”

  子曰:“由,诲女知之乎?知之为知之,不知为不知,是知也。”

  子曰:“见贤思齐焉,见不贤而内自省也。”

  子曰:“三人行,必有我师焉;择其善者而从之,其不善者而改之。”

  曾子曰:“士不可以不弘毅,任重而道远。仁以为己任,不亦重乎?死而后已,不亦远乎?

  子曰:“岁寒,然后知松柏之后凋也。”

  子贡问曰:“有一言而可以终身行之者乎?”

  子曰:“其恕乎!己所不欲,勿施于人。”

1.解释下面各句中画线词语的意思。

(1)吾日三吾身。   省:___________

(2)温而知新。    故:___________

2.用现代汉语翻译下面的句子。

 ①择其善者而从之,其不善者而改之。

 ______________________________________________

 ②己所不欲,勿施于人。

  ______________________________________________

3.曾子曰:“士不可以不弘毅,任重而道远。仁以为己任,不亦重乎?死而后已,不亦远乎?”“士不可以不弘毅”的原因是:_____________,“重”表现在___________,“远”表现在____________。

4.孔子认为,什么样的人才能做老师?这种观点是否与“三人行,必有我师焉;择其善者而从之,其不善者而改之。”的观点相矛盾?

 ______________________________________________