首页
登录
职称英语
An airplane flies because its wings push down on the air flowing past them, a
An airplane flies because its wings push down on the air flowing past them, a
游客
2023-09-26
21
管理
问题
An airplane flies because its wings push down on the air flowing past them, and in reaction, the air pushes up on the wings. When an airplane is level or rising, the front edges of its wings ride higher than the rear edges. The angle the wings make with the horizontal is called the angle of attack. As the wings move through the air, this angle causes them to push air flowing under them downward. A sleeper angle of attack will cause the wings to push more air downward. The third law of motion voiced by English physicist Isaac Newton states that every action produces an equal and opposite reaction. In this case, the wings pushing air downward is the action, and the air pushing the wings upward is the reaction. This causes lift, the upward force on the plane, Lift is often explained using Bernoulli’s principle, which states that, in some circumstances, a faster moving fluid(流体) (such as air)will have a lower pressure than a slower moving fluid. The air on the top of an airplane wing is at a lower pressure than the air underneath the wing, but this is an effect of lift, not its cause.
Lift is one of the four primary forces acting upon an airplane. The others are weight, thrust, and drag. Weight is the force that offsets lilt. because it acts in the opposite direction. The weight of the airplane must be overcome by the lift produced by the wings, if an airplane weighs 4.5 metric tons, then the lift produced by its wings must be greater than 4.5 metric tons in order for the airplane to leave the ground. Designing a wing that is powerful enough to lift an airplane off the ground, and yet efficient enough to fly at high speeds over extremely long distances, is one of the marvels of aircraft technology.
选项
答案
Why does an airplane fly?
解析
根据第一句话“An airplane flies because its wings push down on the air flowing past them,and in reaction,the air pushes up on the wings.”和全篇文章的意思得出。
转载请注明原文地址:https://tihaiku.com/zcyy/3046996.html
相关试题推荐
Thisarticleiswellwrittenbecausespecialattention________tothechoiceofw
Youhavetoraisethequalityofyourproductsbecausebuyersinthosecountries
ZhangGuimeihasearnedtherespectofpeoplebecauseshe________herselffull-t
Jameisunhappybecauseeveryonewenttothedance______her.A、against.B、forC
TomtooknonoticeofwhatIwassayingbecausehethoughtI(cheat)______him.
Shegaveupherjobasanursebecauseshefoundthechildrentoodifficult____
[audioFiles]audio_ehaz20046_001(20046)[/audioFiles]A、Becauseshelikestolive
[audioFiles]audio_ehaz20046_001(20046)[/audioFiles]A、Becausehe’llwritearepo
WhydoestheGmailTeamwritetotheGmailusers?Becausetheuserhasn’tusedh
WhydoestheGmailTeamwritetotheGmailusers?Becausetheuserhasn’tusedh
随机试题
"TheHydrologicCycle"→Thehydrologiccycleisthetransf
【S1】[br]【S2】Peoples→People或persons人们应该是people或persons,Peoples是许多民族。
按照我国《保险法》的规定,投保人因过失违反告知义务,足以影响保险人决定是否同意承
某交换机的配置如下:[SWA]stpmodemstp[SWA]stpreg
Thelightsgoout--anotherpowerfailure.
许赛就读于北京某大学社会工作专业,毕业后进入社会机构工作,许赛的工作属于( )
简述现代企业人力资源管理各个历史发展阶段的特点。
期货从业人员王某利用工作便利,了解到所在公司一些客户的交易信息,王某不仅自己利用
火力发电厂升压站监控系统中,测控装置机柜的接地采用绝缘电缆连接等电位母线总接地铜
关于静态投资和动态投资的说明,下列说法中正确的是()。A.静态投资包括动态
最新回复
(
0
)