首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Weight on and off the Earth We are so used to our life on the surface of the earth that it can be quite an effort for our mi
Weight on and off the Earth We are so used to our life on the surface of the earth that it can be quite an effort for our mi
admin
2014-09-13
66
问题
Weight on and off the Earth
We are so used to our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted. Because we can feel that things are heavy, we think of "weight" as being a fixed quality in an object, but it is not really fixed at all. If you could take a one-pound packet of butter 4, 000 miles out from the earth, it would weigh only a quarter of a pound.
Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4, 000 miles out into space? The reason is this; all objects have a natural attraction for all other objects; this is called gravitational attraction. But this power of attraction between two objects gets weaker as they get farther apart. When the butter was at the surface of the earth, it was 4, 000 miles from the center. When we took the butter 4, 000 miles out, it was 8, 000 miles from the center, which is twice the distance. If you double the distance between two objects, their gravitational attraction decreases two times two. If you treble the distance, it gets nine times weaker(three times three)and so on.
So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth.
What about the weight of our pound of butter on the surface of the moon? At the distance the pull of the earth is about 4, 000 times smaller than it is here on the surface, so we can forget all about the earth-pull on our butter.
On the other hand, on the moon there will be an attraction between the butter and the moon, but the butter will weigh only about one-sixth as much as it does on the earth. This is because the moon is so much smaller than the earth. The amount of gravitational pull that a body produces depends on the amount of material in it. A packet of butter has a gravitational pull of its own; but this is very small in relation to the pull of something as large as the moon, or the earth, or the sun.
According to the passage, "weight" should be understood in the sense that _
选项
A、it is fixed if it is outside the earth’ s gravitational pull
B、it decreases four times when it is 4, 000 miles from the earth’ s center
C、it varies with the change of the gravitational attraction between two objects
D、things increase in amount as they are closer to the earth’ s surface
答案
C
解析
第一段第二句表明,物体的重量并非固定不变。第二段解释说,物体的重量源于物体间的引力。也就是说,物体的重量随着物体间引力的改变而改变。
转载请注明原文地址:https://kaotiyun.com/show/SHQd777K
本试题收录于:
职称英语理工类C级题库职称英语分类
0
职称英语理工类C级
职称英语
相关试题推荐
Americansstillhavebeengainingweight,althoughtheyhavecuttheiraveragefatintakefrom36to34percentoftheirtotald
Americansstillhavebeengainingweight,althoughtheyhavecuttheiraveragefatintakefrom36to34percentoftheirtotald
Americansstillhavebeengainingweight,althoughtheyhavecuttheiraveragefatintakefrom36to34percentoftheirtotald
DangersAwaitBabieswithAltitudeWomenwholiveintheworld’shighestcommunitiestendtogivebirthtounderweightbabie
AinyourbodyBwithoutwaterCbeforelongDforachangeEonabusydayFtoyourweightDehydrationmayoccurifthereis
Menofacertainagearealwaysreadytotalkabouttheirfatproblem.Menusuallybegintoworryabouttheirweightwhenthey
HowMenFacetheFatProblemItisapleasuretoseemenofacertainageworryingabouttheirweight.Listeningtothemisn
SaunaCeremonialbathinghasexistedforthousandsofyearsandhasmanyforms,oneofwhichisthesauna.TheFinnshavepe
SaunaCeremonial(仪式性的)bathinghasexistedforthousandsofyearsandhasmanyforms,oneofwhichisthesauna.TheFinnsha
随机试题
读装配图应从()入手进行概括了解。
复核死刑案件属于狭义的审判监督。
李某和王某正在磋商物流公司的设立之事。通大公司出卖一批大货车,李某认为物流公司需要,便以自己的名义与通大公司签订了购买合同,通大公司交付了货车,但尚有150万元车款未收到。后物流公司未能设立。关于本案,下列哪一说法是正确的?(2016年卷三25题,单选)
进口货物报关单有若干联,下列报关单中()属于报关单的基本联。
金融期权包括看涨期权和看跌期权两种基本类型。()
甲公司的主营业务为船用燃料油的供应服务。为拓展业务范围,2009年甲公司公开发行股票,所募集资金投入到水上加油项目。公司购建了1艘千吨级加油船,2010年上半年已投入开展水上加油业务,2艘800吨级加油船于2010年6月投入运营,另有1艘800吨级加油船将
Thefollowingparagraphsaregiveninawrongorder.ForQuestions41-45,youarerequiredtoreorganizetheseparagraphsintoa
下列叙述中正确的是()。
InthecontemporaryWesternworld,rapidlychangingstylescatertoadesirefor______andindividualism.
A.continuallyB.wastedC.atthetopD.meansE.causesF.everythingG.putH.collectingI.varyJ.appealK.congre
最新回复
(
0
)