Would the plane take off?

[tropical_fishy]

I hate calculus. Can I announce that in this thread? It's semi-math related. I. hate. calculus. Right now. I hate sequences and series, I hate that I have calc at 8:30 in the morning and I rarely go, I hate that I don't remember how to do conditional covergence for the alternating series test, and I don't know how to find sums of p-series. Oh, and magman007 explained the plane thing and I'm all better now.

Back to your regularly scheduled program.

[BD_Paintball]

how is it going to fly when it has no air speed. no lift = not flying

[Miscue]

I hate calculus. Can I announce that in this thread? It's semi-math related. I. hate. calculus. Right now. I hate sequences and series, I hate that I have calc at 8:30 in the morning and I rarely go, I hate that I don't remember how to do conditional covergence for the alternating series test, and I don't know how to find sums of p-series. Oh, and magman007 explained the plane thing and I'm all better now.

Back to your regularly scheduled program.

Study more and it becomes simple! Take some harder math classes and you'll realize how easy Calculus really was.

[tropical_fishy]

Study more and it becomes simple! Take some harder math classes and you'll realize how easy Calculus really was.

I really do like math. I really do like calculus. I just hate tests. And I hate mornings. So when I have tests and mornings, that is extra-super bad.

[gimp]

Just think of it as if you were looking at it from the side, one part at a time. There is a conveyor belt moving 100 mph to the right, and then imagine a 747 moving 100 mph to the left (in the air). Now lower the 747 till it touches the conveyor belt. It will still be moving at 100 mph to the left and the wheels will be spinning at 200 mph. I'm an engineer (not aero or mech) and when I first read it I just didn't think about how a plane actually made itself move and I thought it would stand still. The way the question is worded tricks you into thinking like it's a car.

[gimp]

I really do like math. I really do like calculus. I just hate tests. And I hate mornings. So when I have tests and mornings, that is extra-super bad.

I felt the same way. Graduated from RPI with an EE and CSYS degree. Now I'm working as a nuclear engineer on submarines. I also used to think 8:30 was early, now I'm happy when I get to sleep in till 5. yay!!

[Miscue]

I felt the same way. Graduated from RPI with an EE and CSYS degree. Now I'm working as a nuclear engineer on submarines. I also used to think 8:30 was early, now I'm happy when I get to sleep in till 5. yay!!

Congrats! Working with the Navy?

[Army]

Just think of it as if you were looking at it from the side, one part at a time. There is a conveyor belt moving 100 mph to the right, and then imagine a 747 moving 100 mph to the left (in the air). Now lower the 747 till it touches the conveyor belt. It will still be moving at 100 mph to the left and the wheels will be spinning at 200 mph. I'm an engineer (not aero or mech) and when I first read it I just didn't think about how a plane actually made itself move and I thought it would stand still. The way the question is worded tricks you into thinking like it's a car.

I answered that.
The 747 does not use its wheels to generate forward motion.

[Miscue]

Ok, these are my last thoughts on this:

It is not the case that a conveyor belt can prevent an airplane from moving forward no matter how fast it goes (ideally). The plane does not have to be in a state of flight for this to apply. The median used to propel the plane forward (air) is not moving and that's the important idea here... the moving conveyor belt becomes irrelevant. It is relevant that power is not being applied to the wheels of the plane, I initially didn't think so until I thought about it more. The condition in which the plane is stationary and net velocity is 0... does not occur.

So yes... it can take off because it will generate airspeed and go forward regardless. It still needs enough runway.

Same thing Army and others said basically... now I understand it.

[billybob_81067]

Think this way: the plane is already flying with wheels up, just very low and against the travel direction of the belt. It does not matter the belt speed, the plane flies. Now put the gear down. Does the plane instantly stop? No, it is still at flight speed. The plane does NOT get it's forward thrust/movement from any drive system to the wheels. Forward movement is independant of the belt.

That sir is the best explanation yet! I understood what the people saying "Yes it will fly" were getting at, yet could not think of a real good way to word a description, but you hit it right on the head!

[wanna-b-ballin']

it wont take off. how can a plane get lift if it is not moving forward?

[Army]

it wont take off. how can a plane get lift if it is not moving forward?

Go back, and sloooowly read the original question.

[wanna-b-ballin']

if its already in motion, as in flying, when it comes over the conveyer belt, then sure, it can take off because it will have speed, and lift.

whereas i think the question is stating that the plane and conveyor belt are both at a stop, and both start and accelerate at the same time, thus not moving it anywhere.

i dont see how you guys think it can lift off, unless i'm missing something major.

[bofh]

Case in point: I can take off of an icy runway just as easily as a dry one. Why? My wheels don't "slip" because it is the prop that is pulling me forward. Now...stopping is another issue. My breaks are based at the wheels, stopping on ice is tough. Do you see?

This sounds like the best way to explain that the runway surface friction/direction doesn't really do a damn thing in the take off of the plane.

The plane flies.

[wanna-b-ballin']

with a propeller driven plane, i could see it taking off, as the propeller is directly pushing air over the wings.
where as on a jet, it is sucking air in under the wings, and pushing it out really fast behind the plane. i dont think it gives it lift.