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问题 实验题

（20分）

Ⅰ（10分）

在“探究弹簧弹力大小与伸长量的关系”实验中，甲、乙两位同学选用不同的橡皮绳代替弹簧，为测量橡皮绳的劲度系数，他们在橡皮绳下端面依次逐个挂下钩码（每个钩友的质量均为m=0.1kg，取g=10m/s2），并记录绳下端的坐标X加i（下标i表示挂在绳下端钩码个数）。然后逐个拿下钩码，同样记录绳下端面的坐标X减i，绳下端坐标的平均值Xi＝（X加i+X减i）/2的数据如下表：

挂在橡皮绳下端的钩码个数橡皮绳下端的坐标（Xi/mm）
甲乙
1216.5216.5
2246.7232.0
3284.0246.5
4335.0264.2
5394.5281.3
6462.0301.0
（1）同一橡皮绳的X加i        X减i（大于或小于）；

（2）          同学的数据更符合实验要求（甲或乙）；

（3）选择一组数据用作图法得出该橡皮绳的劲度系数k（N/m）；

（4）为了更好的测量劲度系数，在选用钩码时需考虑的因素有哪些？

答案

（1）小于

（2）乙   （3）  （4）尽可能使伸长量在弹性范围内，同时有足够大的伸长量，以减小长度测量误差

：

（1）小于（因为橡皮绳在伸长后不能完全恢复到原来的长度）

（2）乙（因为甲同学的数据中只有前几个数据可认为在弹性范围内）

（3）

挂在橡皮绳下端的

钩码个数

改变量（Xi-X1）/mm
甲乙
1  
230.215.5
367.530.0
4118.547.7
5178.064.8
6345.584.5
由上表作图得

由图得　

（4）尽可能使伸长量在弹性范围内，同时有足够大的伸长量，以减小长度测量误差。

完形填空
完形填空。
     As my train was delayed for two hours, I had plenty of time to spare. After buying some magazines to read
on the journey, I gave my wife a long-distance call. Then I   1   my way to the luggage office to collect my
heavy suitcase. I had   2   it there three days before. There were quite a few people waiting, and I took out my
wallet to find the receipt   3   my case. The receipt seemed not where I had placed it. No matter how   4   I
searched, the receipt was nowhere to be found.
     When my turn came, I explained the situation sorrowfully to the assistant. The man looked me   5   as if to
say he had heard this kind of story many times and asked me to tell him what my case looked like. I told him it
was an old brown-looking object no different   6   the many cases I could see in his office. The assistant then
told me to   7   a list of what was in the case. If it was correct, he said, I could take the case. I tried to remember
all the things I had hurriedly   8   into the case and wrote them down as they came to me.
     After I had done this, I went to   9   round the office. There were hundreds of cases there. For one fearful
moment, it came to my mind that if someone had found the receipt he could have easily taken the case already.
This had not happened fortunately, for I found the case  10  in the corner. After examining the.things inside, the
assistant was satisfied that it was mine, and told me I could take it.
( )1.A. had           
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( )5.A. here and there
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( )10.A. lying         		B. gave      
B. found     
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C. round and round               
C. of            
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C. walk          
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问答题

某地2004～2009年某家用电器销售量和人均年收入见表2-20，预计到2011年人均年收入较2005年增加36%，年人口增长控制在0.5%以内。甲、乙两公司是该家用电器在国内市场的主要竞争对手，甲公司为了制订主要针对乙公司的竞争战略，运用竞争态势矩阵对两家公司进行了对比分析，见表2-21。基于上述分析，该公司决定将产品重点放在某一特定的目标市场上，向其提供与众不同的产品，不断推陈出新，以高质量、新时尚的形象立足于市场，从而形成竞争优势。

现甲公司拟研制开发出大尺寸的液晶电视推向市场，可采用什么方法预测分析其市场发展趋势？说明理由。
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