问题 探究题

在某次探究活动中,小明对老师给出的“小球在光滑斜面由静止释放时,所处高度越高,到达斜面底端的速度越大,而与小球质量无关”这一结论产生了质疑.他猜想小球从同一光滑斜面上自由滚到底端时的速度,    

猜想一:可能与小球在光滑斜面上的高度无关;  

猜想二:可能与小球的质量有关.

他选择了一些实验器材,进行了如下实验(图中A、B、C分别表示小钢球在第0.1 s末、第0.2 s末、第0.3 s末所处的位置,钢球1、2、3的质量关系为m<m=m):

(1)实验一是为了验证猜想_______(填“一”或“二”),通过该实验他得到的结论是:  小球从同一光滑斜面上自由滚到底端时的速度与小球的质量______(填“有关” 或“无关”).

(2)实验二中,小球2和3在同一光滑斜面的不同高度处同时由静止释放,到达底端时  的速度分别为v、v,请判断v______v (填“>”“=”或“<”).

(3)在完成了以上探究后,小明继续进行“探究动能的大小与速度的关系”的实验三,  根据实验的结果:他得出了,动能越大,你认为他的结论是否可靠?_________(填“可靠”或“不可靠”).原因是________________________.

答案

(1)二;无关  

(2)<  

(3)不可靠;实验中没有使两球质量相同(或者没有用到控制变量法)

阅读理解

Jeanne Calment, a French woman, become a record breaker on 17 October 1995, when at the age of 120 years and 238 days, she became the longest-lived human being on record. A Japanese man died in 1986 at the age of 120 years and 237 days.

Jeanne Calment lives in a small old people’s home in the south of France, her husband, her only child and her grandson have all died. She is nearly blind and deaf and is always in a wheelchair, but her doctor describes here as being “more like a 90-year-old in good health” than someone of 120. She still has a lively sense of humor. When asked on the 120th birthday what she expected of the future, she replied, “A very short one.” She also remarked that she thought the good Lord had forgotten all about her.

So what is the key to a long life? According to some doctors, diet, exercise and no smoking are the three important factors. Jeanne Calment has followed two of the tips. She has always eaten a healthy diet, and she used to do exercises every day until she broke her leg at the age of 115. However, until recently she drank two glasses of strong red wine a say, and she does smoke (now only a little). Besides, Jeanne Calment might have got very good genes from her parents. Her father lived to the age of 94 and her mother to 86.

A local lawyer bought her house when she was 80 under an agreement that he would pay her some money every year until her death. It must have seemed a good move at the time, but so far the lawyer has paid her at least three times the value of the house. Every year on her birthday Jeanne Calment sends him a card saying: “Sorry, I’m still alive!”

小题1: How does Jeanne Calment feel about her old age?

A.She feels upset and unhappy.

B.She is cheerful and humorous.

C.She likes to live much longer.

D.She feels she is going to die very soon.小题2: The text seems to suggest that Jeanne Calment owes her good health and long life to______.

A.smoking only little every day

B.neither smoking nor drinking

C.always drinking two glasses of strong red wine a day and never smoking

D.the good genes from her parents, a healthy diet and some exercises小题3: Which of the following could best explain the underlined word “genes” in the third paragraph?

A.good habits of body-building.

B.Some materials that control the development of a living thing.

C.Comfortable living conditions.

D.Something necessary for a person to keep his life.小题4:Why did Jeanne Calment say “Sorry, I’m still alive!” to the local lawyer?

A.She had an agreement with the lawyer when she was 80.

B.The lawyer has not paid her enough rent yet.

C.The lawyer has paid her more money than the value of the house.

D.The house she sold to the lawyer was worth the money already paid.

多项选择题