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
考研
Experienced baseball fielders can tell how far a ball is going to travel just by listening to the crack of the bat. If they didn
Experienced baseball fielders can tell how far a ball is going to travel just by listening to the crack of the bat. If they didn
admin
2010-01-13
112
问题
Experienced baseball fielders can tell how far a ball is going to travel just by listening to the crack of the bat. If they didn’t, they wouldn’t stand a chance of catching it, claims a physicist in New York.
"When a baseball is hit straight at an outfielder, he cannot quickly judge the angle of the scent and the distance the ball will travel," says Robert Adair, a physicist at Yale University. If he relied purely upon visual information, the fielder would have to wait for about one-and-a-half seconds before he could tell accurately if the pitcher hit the ball long or short. By this time the ball may have travelled too far for him to reach it in time.
To stand a fighting chance of catching it, according to Adair, fielders must listen to the sound the ball hitting the bat to judge how far it will travel. There is anecdotal evidence to support this, he says. A former centre fielder told Adair: "If I heard a crack I ran out, if I heard a clunk, I ran in."
To test his hypothesis, Adair calculated how quickly a fielder could change direction if he had misjudged whether the ball was going long or short. The difference between the "crack" and "clunk” can he explained by how well the batter has hit the ball, and could mean a difference in running distance of as much as 30 metres, he told delegates at a meeting of the Acoustical Society of America in Chicago last week.
Scientists already knew that to hit a ball long the batter must strike it somewhere near the vibrational node of the bat, known as the sweet spot. Balls hit on the sweet spot generate fewer energy-sapping vibrations in the bat, allowing greater energy transfer to the ball. Conversely, mishit balls make the bat vibrate strongly and so do not travel as far.
Adair is quick to point out that this only applies to wooden bats, which are used in major league baseball. Aluminum bats, on the other hand, tend to produce a fairly uniform "ping” sound regardless of where you hit them.
Which of the following statements best summarizes the main idea of this passage?
选项
A、Hitting the ball to produce different sounds is not an easy matter.
B、The sound of the bat may give fielders more chances to catch the ball.
C、Aluminum bats are inferior to the wooden ones.
D、The study of Robert Adair shocks the Acoustical Society of America.
答案
B
解析
主旨大意题。本文主要讲的是防守队员如何根据球击在木质球棒上的声音来判断球的飞行距离。
转载请注明原文地址:https://kaotiyun.com/show/Zjmi777K
0
在职申硕(同等学力)英语
相关试题推荐
Visualimpairment(视觉障碍)carrieswithitareducedorrestrictedabilitytotravelthroughone’sphysicalandsocialenvironmentu
"Businesscasual"wasprevalentseveralyearsagobecause______TheFortune500executives______
Oneofthereasonsfornotstudyingaforeignlanguageinthepastis______.Accordingtothearticle,thegrowthoftheIntern
Man:Youknowwhat?Youshouldinvestthemoneyyourself.Woman:Thathadcrossedmymind.Question:Whatdoesthewomanmean?
ManyAmericansharboragrosslydistortedandexaggeratedviewofmostoftheriskssurroundingfood.FergusClydesdale,headof
Inthephenomenonofatomicfission,thenucleusissplitintotwopiecesofapproximatelyequalmass.
Directions:Inthispart,youaretowritewithin30minutesacompositionofnolessthan150wordsaboutTheEnergyUsedinAm
I’venotreadthefirstchapter,______finishedthebook.
He______allhisunfinishedmanuscriptstohiscolleaguesinthelaboratorybeforehewenttoFrance.
Thisleavesuswiththechallengeoffindingsomepoliticallypracticablewaytoreducegreenhousegasemissions.Butitisana
随机试题
赵孟頫,字子昂,号松雪道人,有________10卷。
在国际私法上,主张以“规则选择”或“结果选择”来替代“管辖权选择”的学者是()
A.DDTB.甲烷C.甲醛D.臭氧E.甲基汞属于内分泌干扰物的是()
下列哪项不是引起左心衰竭的常见原因
根据《建设工程安全生产管理条例》规定,对于某项目达到一定规模的危险性较大的模板工程的专项施工方案经()审批签字后,方可实施。
下列各项中,作为“当期营业利润增加”项目的有()。
下列关于股票分类错误的是()。
某教师将《拿来主义》的教学目标表达为知识与技能目标、过程与方法目标、情感态度与价值观目标三维教学目标,以下表述不恰当的一项是()。
美育
Forthispart,youareallowed30minutestowriteacompositiononthetopic:StatisticsofFamilyExpensesinShanghai.Yoush
最新回复
(
0
)