问题 实验题

某同学设计了一个探究物体质量一定时加速度a与物体所受合力F的关系实验.如图(a)为实验装置简图,实验中,小车运动加速度a可用纸带上点求得,小车的合外力F可以用砂和砂桶总重量代替。若保持小车的质量不变,改变保持砂和砂桶质量m,分别得到小车加速度a与沙桶和沙子质量m数据如下表:(重力加速度g=10m/s2

(1)根据上表数据,为直观反映小车加速度a与小车合外力F的关系,请按照图(b)方格坐标纸中所选择的单位,描点作图。

(2)写出一条上面对提高本实验结果准确程度有益的建议:__________________________________

答案

(1)如下图所示

(2)实验前要先平衡摩擦力 或砂桶和砂子的质量要远小于小车的质量

题目分析:(1)先求得合外力,做直线图,直线形象、直观,便于说明规律,作图时注意,偏离比较远的点可以舍去。

(2)探究加速度与物体质量、物体受力的关系实验中为了减小实验的系统误差,要注意两点:①要平衡摩擦力;②要使小车的质量远大于砝码和砝码盘的总质量。

阅读理解

任务型阅读。阅读短文,根据其内容完成下列任务。

Yesterday evening I went to see a film. After I went into the cinema, I began to look for my seat. It was Number 18, Row 18. I found it easily, but I saw a soldier(士兵) sitting on it. I walked to him and told him that the seat was mine. He said with a smile, “Oh, sorry. My seat is next to yours. Would you like to take that seat and leave this one to me?”

I looked at his seat. It was broken and had no back, so I disagreed. But he still wanted to change our seats. I was      and said loudly, “I don’t want to do that. Are you trying to bully (欺负) me as a soldier?” After      this, the soldier stood up and moved to his seat.

Then I saw my seat was much worse than his seat. There was only a piece of wood (木头) left. It would be very uncomfortable to sit on it. Now I knew why the soldier wanted to change his seat with me. I felt very sorry. The soldier again asked me to take his seat, but I didn’t do that. I sat on the piece of wood till the film finished.

小题1:请根据短文内容,分别写出①、②两处所缺单词。(每空限填一词)

① ________________  ② ________________

小题2:判断下列句子正 (T) 误 (F)。

A. It was a little difficult for the writer to find his or her seat in the cinema. (    )

B. The soldier wanted to take the writer’s seat because it was worse than the solder’s seat

(    )

小题3:把上文中画线的句子译成汉语。

________________________________________

小题4:根据短文内容,回答下列问题。

Did the soldier want to bully the writer?

_______________________________________

小题5:What was the soldier’s seat like?

_______________________________________________________________

单项选择题