问题 实验题

(6分)某同学利用图(a)所示实验装置即数字化信息系统获得了小车加速度a与钩码的质量m的对应关系图,如图(b)所示,实验中小车(含发射器)的质量为200g,实验时选择了不可伸长的轻质细绳和轻定滑轮,小车的加速度由位移传感器及与之相连的计算机得到,回答下列问题:

(1)根据该同学的结果,小车的加速度与钩码的质量成      (填“线性”或“非线性”)的关系。

(2)由图(b)可知,图线不经过远点,可能的原因是          

(3)若利用本实验装置来验证“在小车质量不变的情况下,小车的加速度与作用力成正比”的结论,并直接以钩码所受重力mg作为小车受到的合外力,则实验中应采取的改进措施是      ,钩码的质量应满足的条件是           

答案

(1)非线性(2)存在摩擦力(3)调整轨道倾斜度以平衡摩擦力  远小于小车质量

题目分析:(1)根据该同学描绘的加速度和钩码质量的图象是一条曲线而不是直线,所以是非线性关系。

(2)根据图(b)可知当钩码有一定质量,即细线有一定拉力时,小车加速度仍等于0,说明小车合力等于0,所以可能除拉力外小车还收到摩擦力作用

(3)实验改进部分由两个要求,第一个就是图象不过远点,需要平衡摩擦力,所以调整轨道倾斜度,第二个就是图象时曲线,因为小车的合力即细线拉力并不等于钩码重力,而是拉力只有当时。,图象近似为直线。

阅读理解

阅读理解。

     Some people believe that international sport brings about good will between the nations and that if

countries play games together they will learn to live together. Others say that the opposite is true: that

international contests encourage false national pride and lead to misunderstanding and hatred. There is

probably some truth in both arguments, but in recent years the Olympic Games have done little to support

the view that sport encourages international brotherhood. Not only was there the terrible incident (事件)

with the murder of athletes, but the Games were also ruined by those incidents caused mainly by minor

national contests.

     One country received its second-place medal with great anger after the hockey (曲棍球) final. There

had been noisy scenes at the end of the hockey match, the losers objecting to the final decisions. They

were certain that one of their goals should not have been dismissed and that the opposite side's victory

was unfair. Their manager was angry when he said:"This wasn't hockey. Hockey and the Intemational

Hockey Society are finished." The president of the society said later that such words could result in the

pause of the team for at least three years.

     The American basketball team announced that they would not give away first place to Russia, after

a fighting end to their contest. The game had ended in quarrel. It was thought at first that the United States

had won, by a single point, but it was announced that there were three seconds still to play. A Russian

player then threw the ball from one end of the court to the other, and another player beat it into the basket.

It was the first time the USA had ever lost an Olympic basketball match. The judges discussed the matter

for four and a half hours before announcing that the result would stand. The American players then

decided not to receive the silver medals.

     Incidents of this kind will continue as long as sport is played for honors or money rather than for the

love of the game. The suggestion that sportsmen should compete as individuals (个人), or in non-national

teams, might be too much to hope for. But in the present organization of the Olympics there is far too

much that encourages dangerous nationalism.

1. According to the author, recent Olympic Games have ____.

A. brought about goodwill between the nations

B. made only false national pride

C. hardly showed any international friendship

D. led to more and more misunderstanding and hatred

2. What did the manager mean by saying "...Hockey and the International Hockey Society are finished"?

A. His team would no longer take part in international games.

B. Hockey and the society are both ruined by the unfair decisions.

C. There should be no more hockey matches organized by the society.

D. The society should be dismissed.

3. The author gives the two examples in Paragraphs 2 and 3 to show ____.

A. how false national pride leads to undesirable incidents in international games

B. that sport men have been more troublesome than they used to be

C. that competitiveness in the games discourages international friendship

D. that unfair decisions are common in Olympic Games

4. What conclusion can be drawn from the passage?

A. The organization of the Olympic Games must be improved.

B. Athletes should compete as individuals in the Olympic Games.

C. Sport should be played competitively rather than for the love of the game.

D. International contests lead to misunderstanding between nations.

单项选择题