题干

地球五带中,有太阳直射现象的是(    )

A:南温带

B:北温带

C:寒带

D:热带

上一题 下一题 0.0难度 选择题 更新时间:2018-12-04 01:16:20

答案(点此获取答案解析)

D

同类题3

阅读短文,回答问题:

汽车在高速行驶过程中一旦发生碰撞,车身停止,而乘员则会继续向前与车身撞击,甚至能把挡风玻璃撞碎而飞出车外.在发生交通事故时,安全带能对人体起到缓冲的作用,防止出现二次伤害.在发生严重撞击时,方向盘等处的车载气囊会自动充气弹出,在人体接触到安全气囊时,安全气囊通过气囊表面的气孔开始排气,从而起到缓冲作用,减轻身体所受冲击力,大大减小伤害.

(1)汽车“发动机”通常都是以汽油或柴油为燃料的,汽油、柴油都属于____ (可再生/不可再生)能源;汽车“发动机”一般需要用水来作冷却剂,这是利用了水的____ 的属性.

(2)一辆汽车沿一平直公路匀速行驶30km,消耗了2kg汽油,该汽车与路面间的摩擦力为690N,则此过程中汽油完全燃烧放出的热量为____ J,该汽车“发动机”的效率为____ .(汽油的热值为4.6×107J/kg)

(3)汽油机是汽车的“心脏”,汽油机的____ 冲程将内能转化为机械能.

(4)对于短文中提到的“缓冲”,小华同学提出了自己的猜想:安全带和安全气囊增加人与碰撞物间的接触时间,从而大大减小撞击力.物理兴趣小组的同学共同设计了如下实验方案:在两个相同的玻璃槽中堆放不同厚度的面粉,用同一只鸡蛋从相同的高度先落在面粉厚度大的槽中,留下较深的坑,鸡蛋完好无损;后落在面粉厚度较小槽中,鸡蛋破裂.实验中通过比较____ 来比较撞击时间的长短,根据实验可以验证小华同学的猜想是____ (正确/错误)的.请列举上述“缓冲”的物理知识在生活中应用的一个实例:____ 

同类题4

阅读理解

    In 1863, the great novelist Jules Verne wrote a novel called Paris in the Twentieth Century. In the book he used the full power of his great ability to forecast the coming century. Unfortunately, the manuscript (手稿) was lost until his great-grandson happened to discover it lying in a safe where it had been carefully locked away for almost 130 years. Realizing what a treasure he had found, he arranged to have it published in 1994, and it became a bestseller at once.

    Back in 1863, kings still ruled the ancient world in Europe, with so many poor people working in the fields. And steam power was just beginning to change the world. But Verne predicted that Paris in 1960 would have glass skyscrapers, air conditioning, TV, high-speed trains, gas-powered vehicles, and even something similar to the Internet. Verne described life in modem Paris almost without any mistakes.

    Just two years later Verne made another amazing prediction. He wrote From the Earth to the Moon, in which he predicted the details of the task that sent several astronauts to the moon 100 years later in 1969. He correctly predicted the size of the space capsule, the number of astronauts who would carry out the task, the weightlessness that the astronauts would experience, and the final landing in the ocean.

    How was Jules Verne able to predict 100 years into the future successfully? Although he was not a scientist himself, Verne often turned to scientists, asking them questions about their opinions of the future. He collected a vast amount of information about the great scientific discoveries of his time. Verne realized that science would make it possible for many amazing things to appear in the future. The secret of his successful prediction was his belief in the power of science to change society.