问题 填空题

氢原子中电子和原子核之间距为0.00000000529,用科学记数法表示为(    ).

答案

5.29×10﹣9

完形填空

A girl went to her father to ask for his suggestion. She was having a        time in life, and it seemed that as soon as one problem disappeared another one         in its place.

Her father, a chef, took her into the kichen. He poured water into three pans and put them on to boil. After the water boiled, he put some carrots into the first pan, some         into the second pan and coffee into the last one. He waited without saying a word.

After 20 minutes, her father turned         the stove(炉子), took out the carrots and the eggs and put them in a bowl. He poured the coffee into a cup.

He asked his daughter, “Dear,         do you see?”

“Carrots, eggs, and coffee”, she replied.

“Touch the carrots,” he told her. She did and felt that the carrots were       . After that he asked her to take an egg and break it. She found that the egg was hard.       , her father asked her to taste the coffee.

She asked, “What’s the          , Father?”

Her father said, “As you see, each thing reacted(起反应) differently to the boiling water. The strong and hard carrots became soft and weak after boiling. The fragile(脆弱的) eggs became hard after being cooked. The coffee beans were very special, but they changed in the water, too.”

“Who are you?”asked her father. “When trouble          at your door, how do you react? Are you carrots, eggs,          coffee?”

小题1:A. hard                      B. happy                 C. busy

小题2:A. happended                 B. took                  C. appeared

小题3:A. meat                      B. fish                  C. eggs

小题4:A. on                        B. off                   C. over

小题5:A. what                      B. why                  C. how

小题6:A. delicious                   B. crispy                C. soft

小题7:A. At once                    B. At last                C. At present

小题8:A. meaning                   B. reason                C. consequence

小题9:A. shouts                    B. stares                C. knocks

小题10:A. and                     B. or                   C. but

实验题

(1)(6分)利用图中所示的装置可以研究自由落体运动。实验中需要调整好仪器,接通打点计时器的电源,松开纸带,使重物下落。打点计时器会在纸带上打出一系列的小点。

①为了测得重物下落的速度和加速度,还需要的实验器材有      。(填入正确选项前的字母)

A.天平    B.秒表    C.米尺     D.弹簧测力计

②打点计时器接在频率为50Hz的交流电源上,图11为实验中打出的一条纸带,从起始点O开始,将此后连续打出的7个点依次标为A、B、C、D……。打点计时器打F点时,重物下落的速度为        m/s,该重物下落的加速度为    m/s2。(结果保留两位有效数字)

(2)(12分)某兴趣小组为了测量一待测电阻Rx的阻值,准备先用多用电表粗测出它的阻值,然后再用伏安法精确地测量.实验室里准备了以下器材:

A.多用电表

B.电压表Vl,量程3V,内阻约5kΩ

C.电压表V2,量程15V,内阻约25kΩ

D.电流表Al,量程0.6A,内阻约0.2Ω

E.电流表A2,量程3A,内阻约0.04Ω

F.电源,电动势E=4.5V

G.滑动变阻器Rl,最大阻值5Ω,最大电流为3A

H.滑动变阻器R2,最大阻值200Ω,最大电流为1.5A

I.电键S、导线若干

①在用多用电表粗测电阻时,该兴趣小组首先选用“×10”欧姆挡,其阻值如图12(甲)中指针所示,为了减小多用电表的读数误差,多用电表的选择开关应换用_________欧姆挡;

②按正确的操作程序再一次用多用电表测量该待测电阻的阻值时,其阻值如图12(乙)中指针所示,则Rx的阻值大约是_________Ω;

③在用伏安法测量该电阻的阻值时,要求尽可能准确,并且待测电阻的电压从零开始可以连续调节,则在上述提供的器材中电压表应选           ;电流表应选           ;滑动变阻器应选           。(填器材前面的字母代号)

④在虚线框内画出用伏安法测量该电阻的阻值时的实验电路图.