问题 实验题

(7分)在探究物质某些属性的实验中,有如图所示甲、乙、丙三套完全相同装置,燃料的质量都是10g,烧杯内的液体质量也相同。

(1)比较不同燃料的热值,应选择        两图进行实验;比较不同物质的比热容,应选择      两图进行实验;

(2)实验中,甲与丙的加热时间相同,目的是为了                                  

最后发现丙图中的温度计示数较高,据此可得到的结论是                        

(3)该实验过程主要用到的两种物理研究方法是                         

(4)已知酒精的热值为3.0×107J/kg,完全燃烧10g酒精放出的热量为         J。

答案

(1) 甲、乙 甲、丙 (2) 使水和煤油吸收相同的热量  煤油的比热容较小/煤油的吸热能力较差 (3) 控制变量法 转换法(4)  3×105   

题目分析:(1)比较不同燃料的热值,应选择不同的燃料,而除了燃料不同外其他条件都应该相同,满足条件的是甲乙两图;比较不同物质的比热容,应选择燃料燃烧放出的热量即物体吸热相同,被加热的物体不同,满足条件的是甲丙两图;

(2)实验中,甲与丙的加热时间相同,目的是为了使两装置中燃料燃烧在相同时间内放出热量相同,即水和煤油吸收相同的热量,最后发现丙图中的温度计示数较高,据此可得到的结论是煤油的比热容较小/煤油的吸热能力较差。

(3)该实验过程主要用到质量相同的同种物质温度变化的多少来表示燃料燃烧放出热量的多少,是物理学中的转换法应用;在研究一个量与多个量的关系时物理中常用的方法有控制变量法,所以实验中用到的两种物理研究方法是控制变量法和转换法;

(4)已知酒精的热值为3.0×107J/kg,完全燃烧10g酒精放出的热量为

Q=mq=0.01kg×3.0×107J/kg=3×105J。

单项选择题
单项选择题

There (1) not one type of reading but several according to your reasons for reading. To read carefully, you have to (2) your reading speed and technique (3) your aim (4) reading. Skimming is a technique necessary for quick and efficient reading.

When skimming, you (5) the reading (6) quickly in order to get the (7) of it, to know how it is organized, (8) an idea of the tone or the intention of the writer. Skimming is (9) an activity which (10) an overall view of the text and (11) a definite reading competence.

Skimming doesn’t need reading all the material, but it doesn’t mean that it is an (12) skill for the lazy, because it need a high degree of alertness and concentration.

When you read, you usually start with (13) understanding and move towards detailed understanding rather than working the other way round. But (14) is also used after you have already carefully studied and you need to (15) the major ideas and concepts.

In order to be able to skim quickly and (16) through a text, you should know where to look for what you want. In preview skimming you read the introductory information, the headings and subheadings, and the summary, if one is provided. (17) this skimming, decide whether to read the material more thoroughly, and select the appropriate speed (18) you read.

The same procedure (19) for preview skimming could also be used to get an overview. Another method would be to read only key words. This is done by omitting the unnecessary words, phrases, and sentences.

In order to skim efficiently and fulfill your purpose, (20) practice is necessary.

18().

A.which

B.that

C.at which

D.at that