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
99
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.
If the bat vibrates very little, ______.
选项
A、the fielder is unable to catch the sound
B、the ball will travel to a short distance
C、the ball may receive greater energy
D、the fielder should quickly run in
答案
C
解析
具体细节题。见第5段第2句话:Balls hit on the sweet spot generate fewer energy-sapping vibration in the bat,allowing greater energy transfer to the ball.
转载请注明原文地址:https://kaotiyun.com/show/Ojmi777K
0
在职申硕(同等学力)英语
相关试题推荐
下列哪项不是缺铁性贫血的临床表现
A.关节间隙狭窄,关节边缘有“骨刺”形成B.骨质疏松,关节间隙狭窄,附近骨组织呈磨砂玻璃样改变C.椎体无骨质破坏,脊柱呈“竹节”样改变D.椎体破坏,累及相邻椎体,椎间隙狭窄,伴椎旁梭形阴影脊柱结核的X线表现为
Likemostforeigners,Iaskalotofquestions,someofwhichareinsultinglysilly.ButeveryoneI______hasansweredthosequ
Hemustnotallowthisunusualbarriertostophimfromfightingagainsttheenemy.
Thehugegrowthofglobal"ecotourism"industryisbecominganincreasingconcernforconservationistswithmountingevidenceth
HowmanydollarsdidMissJoanhandtoMr.Greenly?Thephrase"subjecttochangewithoutnotice"suggests______
Comparedwiththeircosmologist(宇宙学家)colleagues,cosmogonists(星源学家)cansoundalittleold-fashioned.EdgarAllenPoeturnedto
Forthesereasons,thenewspaperishaving______problemsinthenorthofthecountry.
Thefindingsofthetwostudiescontradicteachother,thoughbothgroupsofscientistshaveusedthesamemethod.
随机试题
A.进食-疼痛-缓解B.疼痛-进食-缓解C.呕吐酸酵宿食D.腹痛放射至左肩、左上臂内侧E.腹痛放射至右肩、背部
【2014专业知识真题下午卷】高压配电系统宜采用放射式、树干式、环式或其他组合方式配电,其放射式配电的特点在下列表述中哪一项是正确的?()
在用起扣点计算法扣回预付款时,起扣点计算公式为T=P-M/N,则式中N是指()。
为了解国家制定的“十二五”发展规划执行情况,掌握现代服务业发展状况,国务院某部委拟在全国随机选取部分服务业企业和单位开展一次性专项调查。请根据上述资料回答下列问题:该项统计调查项目属于()。
2019年6月20日,陈某因汽车质量问题与经销商达成退车协议,并于当日向税务机关申请退还已纳车辆购置税。经销商开具的退车证明和退车发票上显示,陈某于2018年5月8日购买该车辆,支付价税合计金额223800元,并于当日缴纳车辆购置税19293.10元。应退
甲公司适用的所得税税率为25%,且预计在未来期间保持不变,2013年度所得税汇算清缴于2014年3月20日完成;2013年度财务报告批准报出日为2014年4月5日,甲公司有关资料如下:(1)2013年10月12日,甲公司与乙公司签订了一项销售合同,约定甲
近代史上,顽固派“其貌则孔也,其心则夷也”的指责主要针对下列哪位人物的思想主张?()
重证据,重调查研究,严禁逼供信政策的基本要求是()
阿拉伯—伊斯兰文化的主要中心,包括()。①开罗②巴格达③科尔多瓦④耶路撒冷
Sheoncemadea(n)______appearanceontelevisionbeforeshedecidedtostepawayfromtheentertainmentindustry.
最新回复
(
0
)