英语 英语 日语 日语 韩语 韩语 法语 法语 德语 德语 西班牙语 西班牙语 意大利语 意大利语 阿拉伯语 阿拉伯语 葡萄牙语 葡萄牙语 越南语 越南语 俄语 俄语 芬兰语 芬兰语 泰语 泰语 泰语 丹麦语 泰语 对外汉语

【英语时差8,16】为什么飞盘会飞呢?

时间:2015-12-03 05:42来源:互联网 提供网友:yajing   字体: [ ]
特别声明:本栏目内容均从网络收集或者网友提供,供仅参考试用,我们无法保证内容完整和正确。如果资料损害了您的权益,请与站长联系,我们将及时删除并致以歉意。
    (单词翻译:双击或拖选)
With a gentle flick1 of the wrist on a warm summer day, you can launch a frisbee2 on a long and graceful3 flight.   On this Moment of Science we'll learn why frisbees fly so well.
One reason is something called gyroscopic force. This is the tendency of a spinning object to maintain a stable orientation4. If you throw any round object so it spins as it flies--a record album or compact disk for example--it will tend to fly something like a frisbee. If you throw it horizontally, it will stay horizontal for most of its flight. The leading edge of a CD or record is much narrower than its broad, flat surfaces, so this steady orientation helps reduce air friction5.
Frisbees and compact disks have the same advantages as far as gyroscopic force is concerned, but there's another physical property that gives your frisbee an aerodynamic edge over your music collection. The top surface of a frisbee is curved. It's wider in the middle and tapers6 at the edges somewhat like the wing of an aircraft. This is no accident. Air moves more quickly over a curved surface than over a flat one, and this faster moving air above your frisbee has lower air pressure than the slow moving air beneath it. The higher pressure on the frisbee's bottom pushes gently upward for a longer flight, an effect known as "lift."You can even use lift to make your frisbee fly a curving path. Throw the frisbee not horizontally, but at a slight angle. The lift will push the disk in the direction the curved surface is pointing. Use a sharp enough angle, and the frisbee will swing back toward you like a boomerang!  

点击收听单词发音收听单词发音  

1 flick mgZz1     
n.快速的轻打,轻打声,弹开;v.轻弹,轻轻拂去,忽然摇动
参考例句:
  • He gave a flick of the whip.他轻抽一下鞭子。
  • By a flick of his whip,he drove the fly from the horse's head.他用鞭子轻抽了一下,将马头上的苍蝇驱走。
2 frisbee pzrz1     
n.飞盘(塑料玩具)
参考例句:
  • We always go to the park on weekends and play Frisbee.我们每个周末都会到公园玩飞盘。
  • The frisbee is a light plastic disc,shaped like a plate.飞盘是一种碟形塑料盘。
3 graceful deHza     
adj.优美的,优雅的;得体的
参考例句:
  • His movements on the parallel bars were very graceful.他的双杠动作可帅了!
  • The ballet dancer is so graceful.芭蕾舞演员的姿态是如此的优美。
4 orientation IJ4xo     
n.方向,目标;熟悉,适应,情况介绍
参考例句:
  • Children need some orientation when they go to school.小孩子上学时需要适应。
  • The traveller found his orientation with the aid of a good map.旅行者借助一幅好地图得知自己的方向。
5 friction JQMzr     
n.摩擦,摩擦力
参考例句:
  • When Joan returned to work,the friction between them increased.琼回来工作后,他们之间的摩擦加剧了。
  • Friction acts on moving bodies and brings them to a stop.摩擦力作用于运动着的物体,并使其停止。
6 tapers a0c5416b2721f6569ddd79d814b80004     
(长形物体的)逐渐变窄( taper的名词复数 ); 微弱的光; 极细的蜡烛
参考例句:
  • The pencil tapers to a sharp point. 铅笔的一段细成笔尖。
  • She put five tapers on the cake. 她在蛋糕上放了五只小蜡烛。
本文本内容来源于互联网抓取和网友提交,仅供参考,部分栏目没有内容,如果您有更合适的内容,欢迎点击提交分享给大家。
------分隔线----------------------------
顶一下
(0)
0%
踩一下
(0)
0%
最新评论 查看所有评论
发表评论 查看所有评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:
听力搜索
推荐频道
论坛新贴