问题 实验题

下列有关高中物理实验的说法中,正确的是

A.“探究动能定理”的实验中不需要直接求出合外力做的功

B.电火花打点计时器的工作电压是220V的直流电

C.在用欧姆表“X10”挡测量电阻时发现指针偏角太小,应该换“X1”挡进行测量

D.在“验证机械能守恒定律”的实验中,必须要周天平测出下落物体的质量

答案

答案:A

A、因本实验是用作图法探究W与V的关系的,只需测出以后各次实验时橡皮筋做的功是第一次实验时的多少倍就可以了,不必测出橡皮筋做的功到底是多少焦耳,故A正确。

B、需要了解打点计时器的工作原理以及熟练使用打点计时器。电火花打点计时器的工作电压是220V的交流电,故B错误;

C、欧姆表刻度不均匀,零刻度在最右边,偏角小说明阻值大,要准确测量,应使指针指在中央附近。在用欧姆表“×10”挡测量电阻时发现指针偏角太小,说明待测电阻阻值较大,应换一更大挡,所以C错误

D、在“验证机械能守恒定律”的实验中,要验证动能增加量和势能减小量是否相等,质量约去,不一定需要天平测量物体的质量.故D错误.

答案:A

阅读理解

There is a famous saying from the French politician J.A. Brillat-Savarin that goes: “Tell me what kind of food you eat, and I will tell you what kind of man you are.” It can be easy to not really think about what you eat. For example, whenever you go into a supermarket to buy a drink, it is all too easy to pick up an ice cream or a piece of chocolate as well. You might not even really want them, but sometimes their bright, nice packaging(包装) can be too hard to refuse.

So, in our special food magazine we will show you why you should really pay more attention to what you eat! Food not only influences our health but also our beliefs, customs and personalities. 

The first article will look at the way fast food is leading to obesity (肥胖). The famous cook, Jamie Oliver, has made it his purpose to introduce ideas about healthy eating. In a speech, Jamie Oliver told the world that during the 18 minutes that he gave his speech, four Americans would die because of the food that they ate! Obesity is also a growing problem in China. As China Daily reported in February, the number of obese people under the age of 18 in China has reached 120 million.

Jamie has worked for 10 years to try and fight this problem. Learning about food is important not just because of health problems but also because many people still don’t have enough food today. And we know as the improvement of science sometimes we have to face genetically modified (转基因) food. Don’t worry – we’ll make you know more about all these topics in our special article! 

We’ll also tell you something interesting about food. For example, do you know what the largest food on the menu is all over the world? It’s the roasted camel and it has been served for several hundred years, often stuffed (填满) with chicken, lamb, egg, fish and rice! 

Hopefully by the time you finish reading this edition(版本), you’ll pay more attention to the food that you eat. As Oliver says, food is something that can help us enjoy our life. It is important that we love it!

小题1:Where is J.A. Brillat-Savarin from?

A. America.     B. England.      C. France.       D. Australia.

小题2:Food can influence us in many ways except our ___________.

A.health

B.beliefs

C.customs

D.dreams小题3:Someone is too fat , maybe because he eats too much ______.

A.chicken

B.lamb

C.roasted camel

D.fast food小题4:Which of the following is true according to the passage?

A.Some people may buy some food just because of it’s packaging.

B.Four Americans died because of Jamie Oliver’s speech.

C.We have enough food for all the people in the world now.

D.Chicken is the largest food on the menu all over the world.

填空题