You have an airplane sitting on a moving runway (not fixed). The runway is like a treadmill, and it matches the speed of the plane but in the opposite direction. Can the airplane take off or not? Note that this is a tricky question.
2006-11-15 16:37:00 · 7 answers · asked by Enrique C 3 in Science & Mathematics ➔ Physics
The only effect of the moving runway is to make the wheels spin twice as fast. But the wheels don't make the plane go, it's the thrust of the engines that counts. The plane may experience a little extra drag due to friction in the wheel bearings, but once it develops a little lift that goes away.
2006-11-15 18:32:20 · answer #1 · answered by injanier 7 · 1⤊ 0⤋
According to Bernoulli's Principle, the reason an aircraft takes off is because the air traveling over the top of the wing causes a state of lower pressure than the air traveling slower below it. Due to this unbalanced pressure, the wing generates lift, and the plane takes off.
In the situation at hand, the total overall motion of the plane is 0; the only thing moving would be air through the engine(s), the wheels, and the treadmill.
Unless the air moved by the engine somehow generates enough airflow around the wing, no movement of air around the wing = no lift, which means that the airplane cannot take off.
Since you said it was a tricky question however...um...maybe if it's on a treadmill in a wind tunnel...
Good luck!
2006-11-15 17:16:56 · answer #2 · answered by youngho1999 1 · 1⤊ 3⤋
Yes, but tricky only in that everything about the treadmill is irrelevant. Conservation of momentum says that backward momentum of the exhaust is balanced by the forward motion of the plane. Therefore, the plane must take off as usual.
This is a variation of the question of why a rocket can go through space if there's nothing to push against.
The question is attempting to mislead you into thinking that the plane's forward motion is because the wheels are pushing against the runway, but a plane is not a car. The plane's wheels are not connected to a motor, hence cannot participate in the plane's propulsion, so the fact that the wheels are doing something different than usual is irrelevant.
2006-11-15 16:50:45 · answer #3 · answered by arbiter007 6 · 3⤊ 2⤋
The earth is revolving about its axis. You can take the revolving earth as a gigantic treadmill moving (covering 1 revolution in 24 hours) at 1,670km/hr and this speed is more than 1.5 times the average speed of a commercial airplane. Airplanes, all over the world, take off in different directions (some against earth's rotation, and some in line with earth's rotation), and whether planes can take off or not, the fact is self-evident.
2006-11-15 17:48:02 · answer #4 · answered by dreamofyz 2 · 0⤊ 1⤋
How do you get LIFT if the air is not moving across the wing? That is how an airplane flies.
Lift + thrust > weight + drag ( said the Flying Nun ).....
2006-11-15 16:49:44 · answer #5 · answered by Anonymous · 1⤊ 3⤋
No the plane cannot even move therefore it cannot take off because it has no forward momentum..and besides if it was possible dont you think we would be using this type of take off senario instead of aircraft carriers if it was possible?
If that aint the answer....then u boggled my mind...please let me know what it is
2006-11-15 16:59:09 · answer #6 · answered by rcossy1023 2 · 1⤊ 3⤋
no lift man, no lift...
btw, how can it match the speed of a non moving plane?, huh...
2006-11-15 18:30:03 · answer #7 · answered by tim s 3 · 0⤊ 1⤋