In cold, damp weather, the buildup of ice on airplane wings can pose significant aerodynamic problems. Which of the following effects would you expect?
AAs ice builds up on the top of the wing, drag increases.
BAs ice builds up on the top of the wing, lift increases.
CAs ice builds up on bottom of the wing, lift decreases.
DAll of the above
参考答案
参考解析:
To answer this question, you need to understand the concepts of lift and drag. You also need to recognize that Table 1 provides the data relevant to the question. Ice building up on top of the wing would increase lift, since the higher the curved upper surface of the wing, the greater the difference between the speed of air moving under the wing and above it. It would also increase drag, as suggested by the third column of Table 1: notice how the wings with the higher upper surface also have greater drag. Finally, ice building up under the wing would decrease the speed of air moving under the wing and so reduce lift. Thus, all three effects would occur.
A cold front moving in from the northwest can produce().Athunderstorms,hail,and then rapid clearingBincreasing cloud cover lasting for several daysClengthy wet weatherDlow ceilings with thick cirrus cloud
Especially in adverse weather,risk of collision with an offshore supply vessel increase when the vessel is moored to what side of the unit?().AUpwindBDownwindCCrosswindDDowncurrent