(20點)點解蒼蠅可以o係飛機入面以一樣速度飛?

The fly is flying in the air inside the aircraft. The aircraft is a closed body and the air inside moves at the same speed with the aircraft. Just imagine if the air inside is not moving together with the aircraft, you would feel a very very strong wind when you are travelling in an aircraft. To the fly, it will just feel the same as if it is flying in still air.

This explains why when we are travelling, e.g. in a train, if the windows of the train comparment are open, we usually fell very strong wind blowing towards us. It is because the wind, which comes from outside the train, is initially not moving, hence has to pick up speed in order to go with the train. This produces the wind that we felt when we sit near to the open window. We won't feel such strong wind if we are travelling in a train compartment with all windows closed.

蒼蠅冇掂到架飛機,不過o係飛機入面以一樣速度飛,佢架力o係邊度黎?
佢冇可能同飛機有一樣o既speed 同 acceleration, o係咩俾force 佢呢?

its force from the air in the aeroplane.
appart from acceleration,its that important of inertia,
all the things inside the aeroplane have same displacement as the aeroplane,
as inertia,
when the aeroplane moved and the fly moved,the inertia affect the fly from the aeroplane,is a force to stop the aeroplance,since the inertia,the fly will fall in the front of its own location,

你可以把飛機想像成一個鐵箱，裡面充講空氣。
飛機加速時，空氣也一同加速。如果裡面有一隻蒼蠅，牠也會一同加速。甚麼推動蒼蠅呢？就是空氣。飛機加速時，假設蒼蠅的頭和飛機的頭是同一方向，蒼蠅雖然停在空氣中，但牠會感到一種力在推牠的尾部。換一個說法，蒼蠅尾的氣壓會比蒼蠅頭的氣壓大。

個力響飛機度黎架。
當飛機飛行既時候會有慣性，入面任何野都係用飛機一樣速度，只係飛機入面既人唔覺得，不過每一樣野都係同飛機一樣速度。

其實任何物體都有慣性。
牛頓定律第一條：靜者常靜，動者常動。
http://elearning.stut.edu.tw/mechanical/Dynamics/ch13/13-1.htm

http://forum.phy.ntnu.edu.tw/demolab/phpBB/viewtopic.php?topic=8134