问题 问答题

某同学为了探究温度升高时吸收热量的多少与哪些因素有关,做了如下实验:在四个相同的烧杯中分别盛有水和煤油,用同样的加热器加热,下表是他的实验数据记录:

烧杯号液体质量(g)初温(℃)末温(℃)加热时间(min)
120020288
210020284
3煤油20020284
4煤油20020242
请根据表中的实验记录回答:

(1)该同学在本次实验中用同样的加热器的目的是______.

(2)比较______ 烧杯号的实验记录,得出的结论是物体温度升高时吸热的多少与物质种类有关.

(3)分析第3、4两个烧杯号的实验数据,可以得出的初步结论是:______.

答案

(1)实验中用同样的加热器,放出的热量才相同,物质吸收的热量才会相同,故用同样的加热器的目的是在相同的时间里吸收的热量相同.

(2)1、3中初温、末温相同,质量相同,物质的种类不同,加热时间不同,说明相同质量的水和煤油,升高相同温度,吸收的热量不同.

(3)比较3、4记录,3杯煤油的质量是200g,升高8℃用的时间是4分钟;4杯煤油的质量是200g,升高4℃用的时间是2分钟,而每分钟吸收的热量是相等的,因此第3杯水吸收的热量多,故说明:相同质量的同种物质,升高的温度越多吸收的热量也越多.

(1)在相同的时间里吸收的热量相同;

(2)1、3;

(3)相同质量的同种物质,升高的温度越多,吸收的热量也越多.

单项选择题

When two of the world’s richest and mightiest men pledge to destroy an enemy, it is time to pay attention. Bill Gates, the former boss of Microsoft who now devotes all his time to his charitable foundation, travelled this week to New York, the city run by Michael Bloomberg, to join his fellow billionaire’s campaign to stamp out smoking.

Have the two potentates met their match Despite decades of work by health campaigners, more than one billion people still smoke today. Smoking kills up to half of those who fail to quit puffing, reducing their lives by an average of 10 to 15 years. The World Health Organisation (WHO) says more than 5 million people a year die early from the effects (direct or indirect) of tobacco. That exceeds the combined toll of HIV/AIDS, tuberculosis and malaria.

Despite that dismal situation, there are three reasons to give the latest pair of campaigners a slim chance of success: money, methods and motivation. Messrs Gates and Bloomberg vowed to spend a combined total of $ 500 million on discouraging the weed. Since Mr. Bloomberg’s charity had already announced an award of $125 million earlier, the new money pledged this week totalled a "mere" $ 375 million: $ 250 million from the mayor, and a fresh $ 125 million from the software magnate’s philanthropic outfit.

How will this cash be spent In quite innovative ways, and that is a second reason for optimism. Hitherto, most anti-smoking funds have been channelled through a few large bureaucracies. But Mr. Bloomberg’s charity wants to let a thousand flowers bloom: in other words, to lend a hand to many initiatives, both public and private, to see what works. There will be a competitive grant scheme for poor countries where the tobacco habit is spreading.

The very fact that two giants are teaming up is a landmark in American philanthropy- comparable to Warren Buffett’s decision, two years ago, to put his fortune at the disposal of Mr. Gates’ foundation. As part of their joint commitment, Mr. Gates is giving some of his $ 125 million directly to Mr. Bloomberg’s charity; the rest will go to carefully monitored projects in India, China and other places where the number of smokers is rising relentlessly.

Then there is motivation. There are other big players in this cause, and that should induce every new entrant to try bringing something fresh to the party. Earlier this year the WHO started a campaign against tobacco known as MPower. One of its selling points was that in contrast with many other projects, it had a fairly clear idea about what was needed. WHO experts have listed a series of tactics, ranging from aggressive public education to a rise in tobacco taxes, that deliver results. (Even if high taxes lead to some smuggling and diversion, studies done in Brazil, for example, show that fiscal measures do curb consumption. ) The World Bank, which funded that research, is also thought to be ready to join the anti-smoking scrum after years of paying little attention.

A crowded field, indeed. But having an extra $ 500 million from two hard-driven billionaires surely won’t hurt.

What can we infer from the last paragraph about the author’s attitude towards this campaign ()

A. Neutral

B. Negative

C. Affirmative

D. Not sure

多项选择题