问题 问答题

对城市生活垃圾的有效处理,是节能、环保的一项重要举措.收集的生活垃圾经过处理分成三类物质:一类是固体垃圾,经填埋、碾压、消毒、覆盖后恢复植被可供郊游、观光;一类是生活垃圾渗沥液,将渗沥液收集起来,用高压泵和压力管道输送到污水处理厂;一类是垃圾气体,其主要成份为甲烷(CH4),可将它收集起来加以利用,每千克生活垃圾经特殊处理后平均能产生0.07m2的垃圾气体,已知该气体的热值为8.1×m7J/m3.请回答下列问题:

(1)这0.07m3的垃圾气体完全燃烧后产生的热量是多少?

(2)若将这些热量全部用来烧水,可使多少kg的水从25℃升高到100℃?

[水的比热容为4.2×103J/(kg•℃)]

(3)若将这0.07m3垃圾气体完全燃烧后所产生热量的50%用来提起一质量为20t的物体,能把该物体提高多少米?(g取10N/kg)

答案

(1)垃圾气体完全燃烧后产生的热量Q=qV=8.1×107J/m3×0.07m3=5.67×106J;

(2)因为Q=Q;则根据Q=cm(t-t0)得:

m=

Q
c(t-t0)
=
5.67×106J
4.2×103J/(kg•℃)×(100℃-25℃)
=18kg.

(3)∵W=Qη=5.67×106J×60%=3.402×106J,

∴该物体提高的高度h=

W
G
=
W
mg
=
3.402×106J
20×1000kg×10N/kg
=17.01m.

答:(1)这0.07m3的垃圾气体完全燃烧后产生的热量是5.67×106J;

(2)若将这些热量全部用来烧水,可使18kg的水从25℃升高到100℃;

(3)能把该物体提高17.01m.

阅读理解

第二节 简答题(共3小题,每小题2分,满分6分)

阅读下面短文,根据73-75题的具体要求,简要回答问题。

Shanghai is the largest city in China. About eleven million people make their homes in Shanghai and its suburbs. This extremely large city spreads out along the banks of the Huang Pu River, which flows into the mouth of the Yangtze River about fourteen miles north of here. Large oceangoing ships travel to Shanghai by way of the Yangtze and the Huang Pu.

Shanghai was a small, unimportant city until 1842 when China lost a war with Great Britain. The British realized that Shanghai was in an excellent location to serve as a seaport for the densely(密集) populated Yangtze River Plain. They forced the Chinese to allow English traders to settle on the wastelands outside the city walls. Later, French, American, and Japanese traders also came to Shanghai. The foreigners built whole new sections of Shanghai, including homes, stores, factories, and office buildings. Thousands of Chinese poured into Shanghai in search of jobs. Most of them settled in the old part of the city. As time passed, shanghai became one of the busiest seaports in the world.

73. Where do most people in shanghai make their homes? (回答词数不超过7个)

_________________________________________________________________.

74. What is the purpose of the Chinese people’s coming into Shanghai ?

(回答词数不超过4个)

_________________________________________________________________.

75. Before 1842, what was the Yangtze River Plain like? (回答词数不超过4个)

________________________________________________________________.

单项选择题