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Chen Liguo <cliguo@...> wrote:
About the the 4th point, there is no need to argue about. It is very obvious from that map.About the 2nd point, the accelaration is centripetal accelaration.The 3rd point, you should think more. The airplane can adjust lift by "attack angle" mechanism. So the airplane, should be in the same height, but with different lift. The difference between lift and weight can provide the centripetal force. Again, my calculation is this force extremly small, for normal airplane speed(absolute speed), which is 10e5 times smalller than gravity force. So the difference caused by directions is even smaller. That is also the point I mentioned in last email.Liguo
rui zhang <zhruirui@...> wrote:To Liguo and Fei,
Thank Liguo for the nice webpage. I also thought about this problem last night and
got similar conclusion (although I don't know why the wind is from east to west).
Here are some comments:
1. About the wind: First, all air around earth moves with the same angular velocity as earth. In this case, there is no wind: means we feel nothing since we are moving
with earth by ourselves. Second, there is the heat from the sun and pressure difference on different area and so on. Then air have relative motion to the earth, this is what we call wind (as explained in the second website you offered).
2. I don't know which angular accelaration Liguo is calculating. The earth is rotating in a constant angular velocity. There should be no angular accelaration at all!
3. I have a prediction. If we say the speed of airplane (relative to the earth) is faster from west to east, due to the effect of the wind, then we should have following prediction: the hight of the airplane will be higher when the airplane is from west to east than from east to west. The reason is: even though the relative speed is the same, the absolute speed of the airplane is different. If we consider the airplane
is doing a part of the circular motion around the center of the earth, its speed is higher if it fly from west to east. For the higher speed, we have the same centripitual force (gravitation force - elevation force from air which is proportional to the relative speed), then the radius of circular motion must be larger. But this hight difference could be very small.
4. On the second website, I saw a map of the direction of winds. It looks like it is not
always from west to east. So it is possible to some airlines we fly faster from east to west. What do you think?
Rui
On 6/4/06, Chen Liguo <cliguo@...> wrote:It is mainly because of the winds effect. Here is the link from internetJust like we said, it is mainly because of the winds. But the directions of the winds are not simply from the earth rotation. Here is another link about the windsAlso to Zhang Rui, we can regard the system as inertial system, since the angular velocity induced force is very small compared with the gravity. I did the calculationrotation acceration is about 10 e-5 which is much smaller than g=9.8.Well it is a nice discussion with you guys!Liguort
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