问题 实验题

某同学设计了如图所示的装置来探究加速度与力的关系。弹簧秤固定在一合适的木板上,桌面的右边缘固定一支表面光滑的铅笔以代替定滑轮,细绳的两端分别与弹簧秤的挂钩和矿泉水瓶连接。在桌面上画出两条平行线MN、PQ,并测出间距d。开始时将木板置于MN处,现缓慢向瓶中加水,直到木板刚刚开始运动为止,记下弹簧秤的示数F0,以此表示滑动摩擦力的大小。再将木板放回原处并按住,继续向瓶中加水后,记下弹簧秤的示数F1,然后释放木板,并用秒表记下木板运动到PQ处的时间t。

(1)木板的加速度可以用d、t表示为a=____________;为了减小测量加速度的偶然误差,可以采用的方法是(一种即可)___________________。

(2)改变瓶中水的质量重复实验,确定加速度a与弹簧秤示数F1的关系。下列图象能表示该同学实验结果的是____________。

(3)用加水的方法改变拉力的大小与挂钩码的方法相比,它的优点是____________。

A.可以改变滑动摩擦力的大小

B.可以更方便地获取多组实验数据

C.可以比较精确地测出摩擦力的大小

D.可以获得更大的加速度以提高实验精度

答案

(1);保持F1不变,重复实验多次测量,求平均值

(2)C

(3)BC

阅读理解

In China, the National Holiday is a big festival and it is to celebrate the founding of the People's Republic of China by Mao Zedong in 1949.Besides from the Spring Festival, the National Holiday is the only other week-long public break from school and work.

As one of the only opportunities  for workers to go home, visit their families or to travel around the country, all hotels, tourist attractions, trains, buses and airplanes around the country are completely packed with holidaying Chinese people.

Are you sorry for not traveling during the National Day ? If you stay at home at that time, I think you are very lucky. Why? Because there are too many people everywhere. In many places of interest in China, it’s too crowded to do anything.

Look at the picture. It was too crowded on the Great Wall on October 1st, 2012. You even couldn’t take photos for you or your friends. All that we could see were people. It was reported that there were about twenty people per meter on the Great Wall. My friends told me they could see nothing but many people on the Great Wall. “We couldn’t walk if the people in front of us didn’t walk,” he said. He showed us a photo on the Great Wall. In the photo, we hardly found him out, there were too many people.

So some people give the advice that we should not have the gold week any more. But other people say no about this advice. What’s your idea of it? Are you sorry now for not traveling during the gold week? I love staying at home more than traveling next National Day.

小题1: How did the writer feel about staying at home on National Day?

A.He believed it was interesting to stay at home on National Day.

B.He believed it was boring to stay at home on National Day.

C.He felt lucky to stay at home on National Day.

D.He felt sorry to stay at home on National Day. 小题2:How many days can people have a break on the Spring Festival.

A. 5 days        B.7 days          C.10 days      D 15 days

小题3:Which of the following is TRUE about the Great Wall on National Day?

A.You could find yourself easily on the photos you took that day

B.You could walk as you like on the Great Wall

C.There were about 30 people per meter.

D.All that could you see on the Great Wall were people.小题4:Where do you think is the article from?

A.www.chinabus.com

B.www.movies123.com

C.www.chinatourist.com

D.www.storyhouse.com

单项选择题