赵显同学学习了“功率”后,对测功率产生了兴趣,他请李沁帮忙,测他做俯卧撑时的功率

题型:问答题

问题:

赵显同学学习了“功率”后,对测功率产生了兴趣,他请李沁帮忙,测他做俯卧撑时的功率.

(1)做俯卧撑时人的身体部分可以近似的看成是一个______.(填一个简单机械的名称)

(2)所需准备的测量工具有体重计、刻度尺和______.

(3)赵显同学共做了20个俯卧撑,做前10个较快,后10个明显有点“力不从心”,则他做后10个俯卧撑的功率______(选填“大于”、“等于”或“小于”)整个20个的平均功率.

(4)体重是500N的沈思邈想粗略的测出自己做俯卧撑的功率,他先用刻度尺测出OA=1m,B到O点的距离OB=1.5m,自己手臂的长约60cm,10s内做了8个俯卧撑,则他的功率约是______W.

考点:功率的计算功率的测量实验杠杆的平衡条件
题型:问答题

单词拼写

1. I have been trying to ____________ (联络) my uncle but I can't get through.

2. Being unable to move freely, he has learnt to keep his heart open and ____________ (交流) thoughts with his readers.

3. The lecturer will talk about the similarities and differences in the Chinese and American school

____________ (体制).

4. He appeared ____________ (放松) and confident before the match.

5. The young champion made a moving short speech at the awards ____________ (仪式).

6. After the written test and interview, Jackson came to the c____________ that Mr. Li was not fit for the position.

7. The lectures c____________ many subjects --- arts, education, philosophy, etc.

8. My mum stood there, watching until the train disappeared in the d____________.

9. My parents looked a____________ at the news that I had won the competition.

10. His teaching is so well o___________ and clear that we all learn actively.

题型:问答题

设备工程合同索赔的构成条件有( )。

A.合同依法生效

B.索赔方发生实际损失

C.索赔方无过错

D.符合索赔依据

E.索赔方提起诉讼

题型:问答题
某同学让激光束通过自制双缝,观察在光屏上形成的双缝干涉条纹.如图所示.关于该同学的操作过程及对应看到的现象,下面几种叙述正确的是(  )

A.仅将光屏移近双缝,光屏上干涉条纹间距变窄

B.仅将激光器移近双缝,光屏上干涉条纹间距变宽

C.仅换一个两缝之间距离较大的双缝,光屏上干涉条纹间距变窄

D.仅将红色光源的激光器换成蓝色光源的激光器,光屏上干涉条纹间距变宽

题型:问答题

流行性出血热的传播途径主要是()

A.虫媒传播

B.动物源性传播

C.垂直传播

D.空气传播

E.土壤传播

题型:问答题

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A.吐温80是非离子表面活性剂
B.吐温80在碱性溶液中易发生水解
C.吐温80可作O/W型乳剂的乳化剂
D.吐温80的溶血性较强
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