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
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
2013-02-16
37
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 traveled 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 1 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 be 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.
According to Robert Adair, why can’t an outfielder rely purely on visual information?
选项
A、Because it may take longer time for him to exert judgment.
B、Because the ball may change directions during flight.
C、Because the ball may be hit either long or short.
D、Because light travels faster than sound.
答案
A
解析
根据文章第二段最后两句“If he relied purely upon visual information….traveled too far for himto reach it in time.”可知,如果仅凭视觉信息,外场员就必须要等待1.5秒才能准确判断出投手是长击还是短击。在这个时候,球已经飞行了太远,外场员已经不能及时抓住它了。据此判断,答案是A。
转载请注明原文地址:https://kaotiyun.com/show/BhmO777K
0
考博英语
相关试题推荐
LastyearFrenchdriverskilled【1】than5,000peopleontheroadsforthefirsttimeindecades.Creditgoeslargely【2】the1,000
Theessenceofbeliefistheestablishmentof______.Differentbeliefsaredistinguishablebythedifferentmodesofactionto
(1)GeraldFeinberg,theColumbiaUniversityphysicist,oncewentsofarastodeclarethat"everythingpossiblewilleventually
Forfarmershopingforahealthyharvest,thebestplacetoturnforhelpthesedaysistheMonsantoCorp.Oneoftheworld’sle
SomeofmyclassmatesinthesamedormestablishedachattinggroupontheNetwhenbroadbandwasavailableoncampus.Thenever
Whereonestageofchilddevelopmenthasbeenleftout,ornotsufficientlyexperienced,thechildmayhavetogobackandcaptu
In1784,fiveyearsbeforehebecamepresidentoftheUnitedStates,GeorgeWashington,52,wasnearlytoothless.Sohehireda
Itisgenerallyacknowledgedthatfamiliesarenownotascloseastheyusedtobe.Givepossiblereasonsandyourrecommendatio
StandingontherimoftheGrandCanyon,gazingacrossthisgiantwoundintheEarth’ssurface,avisitormightassumethatthe
IntheUnitedStates,thefirstdaynurserywasopenedin1854.Nurserieswereestablishedinvariousareasduringthe【51】halfo
随机试题
在执行一次信息传输操作时所花的三部分时间中,与信息所占的扇区位置有关的是_______时间。
DreamsDreamsdonothappenwhenyou’reasleep.Theyhappenwhenyou’reawake.Whateveryourgoalsare,alwaysremember
居民甲与金山房地产公司签订了购买商品房一套的合同,后因甲未按约定付款。金山公司起诉至法院,要求甲付清房款并承担违约责任。在诉讼中,甲的妻子乙向法院主张甲患有精神病,没有辨别行为的能力,要求法院认定购房合同无效。关于本案的说法,下列哪一选项是正确的?(200
在国际上,一般把项目定义为“一种()的创造一项唯一产品和服务的任务”。
有关行政处罚的决定,下面说法正确的有()。
促进人的发展从潜在可能状态转向现实状态的决定性因素是教育。()
(1)法院对案情作了调查(2)被告找了辩护律师(3)法庭认为被告理由不充分(4)甲方因乙方拖欠债务不还而向法院起诉(5)法庭判决被告偿还所欠原告债务
A、 B、 C、 D、 D
阅读以下说明,回答问题。(2010年上半年下午试题五)[说明]某单位网络内部部署有IPv4主机和IPv6主机,该单位计划采用ISATAP隧道技术实现两类主机的通信,其网络拓扑结构如图3-14所示。路由器R1、R2、R3通过串口经IPv4网络连接,路由器R
Applet生命周期是指从Applet【】到浏览器,到用户退出浏览器,终止Applet运行的过程。
最新回复
(
0
)