首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
Learn about Light 1 Ancient civilizations were amazed by the existence of li...
Learn about Light 1 Ancient civilizations were amazed by the existence of li...
admin
2020-12-24
44
问题
Learn about Light
1 Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed thatlight was made up of countless, tiny particles that enter the human eye and create what we call vision. However , Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them, light spread out and travelled like a straight line. This theory was accepted during the 19th century.
2 In 1905,Albert Einstein published a research paper in which he explained what is referred to as the photoelectric effect. This theory explains that particles make up light. The particles Einstein was referring to are weightless bundles (束)of electromagnetic (电磁) energy called photons (光子)_ Today, scientists agree that light has a dual ( 二重) nature — it is part particle and part wave. It is a form of energy that allows us to see things around us. .
3 Things that give off light are known as sources of light. During the day, the primary source of light is the sun. Other sources of light include stars, flames, flashlights, street lamps and glowing gases in glass tube.
4 When we draw the way light travels we always use straight lines. This is because normally light rays travel in a straight line. However, there are some instances that can change the path and even the nature of light. They are reflection, absorption, interference (干扰),etc.
5 Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel (旋转齿轮)between the beam and the mirror. From the rate of rotation of the wheel,number of wheel’s teeth and distance of the mirror, he was able to calculate that the speed of light is 313 million meters per second. In a vacuum (真空),however, the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane.
Air is helpful to increase __
选项
A a straight line
B a beam of light
C sources of light
D the path of light
E a form of energy
F the speed of light
答案
F
解析
根据本文最后一段的最后两句话,即在真空中的光速比在空气中的光速慢,可以推断 出空气有助于提高光速。
转载请注明原文地址:https://ti.zuoweng.com/ti/679QKKKQ
相关试题推荐
Theydidn’tseemtoappreciatethemagnitudeoftheproblem.A.existenceB.caus
共用题干 OlderVolcanicEruptionsVolcanoesweremoredestructiveinancienthist...
共用题干 OlderVolcanicEruptionsVolcanoesweremoredestructiveinancienthist...
共用题干 OlderVolcanicEruptionsVolcanoesweremoredestructiveinancienthist...
共用题干 OlderVolcanicEruptionsVolcanoesweremoredestructiveinancienthist...
第三篇TheWorld’sBest-SellingMedicine Sinceancienttimes,peopleallover...
第三篇TheWorld’sBest-SellingMedicine Sinceancienttimes,peopleallover...
弟一篇TheWorkfsBest-Se川ngMedicine Sinceancienttimes,peoplealloverthe...
弟一篇TheWorkfsBest-Se川ngMedicine Sinceancienttimes,peoplealloverthe...
Theydidn’tseemtoappreciatethemagnitudeoftheproblem.AexistenceBcause
随机试题
下列交易或事项中,应作为企业的短期借款进行核算的有()。 A、A公司将账面价值
下列降压药物中,属于利尿剂的是 A、卡托普利 B、硝苯地平 C、阿米洛
关于巷道掘进中的钻眼工作,说法错误的是( )
下列关于胆汁酸的叙述正确的是
某公路工程地基由黏土组成,动荷载作用下的极限承载力为380kPa,静荷载作用下的
扩张型心肌病的主要临床表现是 A心音减弱 B左室明显扩大
因重大误解订立的合同属于()。 A.有效合同B.无效合同 C.效力未定的
车在这种条件的道路上,最高速度不能超过每小时50公里。
对各种类型癫痫有一定疗效的抗癫痫药的是A.苯妥英钠B.卡马西平C.丙戊酸钠D.乙琥胺E.地西泮
根据《工业炉窑大气污染物物排放标准》,下对炉窑的建设要求表述不正确的是()。A:一类区内禁止新建各种工业炉窑B:一类区内禁止新建各种炉窑,包括市政、建筑施工临