Airplane on a Conveyor conundrum

[Snorkel]

I think we all know what is intended by the question whether it is specific or not - I don't believe it's a trick question like not mentioning it in space for example. But I see Slugsie's point now (the way he is thinking).

Few notes though:
QUOTE: HOW, ON THE FACE OF GODS GREEN EARTH CAN THE CONVEYOR GRIP A ROLLING WHEEL????

----FRICTION!! Why does your car eventually roll to a stop if you don't apply the brakes??

QUOTE: There is NO FORCE acting on it. Why can't you understand that?

----YES THERE IS!! For every force there is an equal and opposite force (some of these forces are negative) - this is basic physics my friend

QUOTE: The forward/backward speed of the conveyor will have no influence on the ability of the aircraft to gain airspeed and fly.

---- Of course it does. If the belt moves in the same direction it helps the plane, if it goes in reverse it hinders the plane!!

The plane cannot move forward unless it produces more power than that which the conveyor belt is taking away from it! By not moving forward there is no air to create the lift.

HOWEVER the question states the plane IS moving forward (possible paradox), but if the plane IS moving forward RELATIVE to me on the solid ground, and the conveyor moves away from me at the same speed, then yes the plane could take off (as it's stated it's still going FORWARD hence able to get lift, just it's 'ground speed' (on the conveyor) is much faster than compared to me).

[dieselboy]

Nope, why would I say that.

you will say that because now your being fussy about who is driving the plane!

just face the fact that if the conveyor moves, the plane wont take off.

and if it moves relative to the plane like your question, then it will take off. but only because the conveyor doesnt actually go anywhere at all.

[dieselboy]

I think we all know what is intended by the question whether it is specific or not - I don't believe it's a trick question like not mentioning it in space for example.

QUOTE: HOW, ON THE FACE OF GODS GREEN EARTH CAN THE CONVEYOR GRIP A ROLLING WHEEL????

----FRICTION!! Why does your car eventually roll to a stop if you don't apply the brakes??

QUOTE: There is NO FORCE acting on it. Why can't you understand that?

----YES THERE IS!! For every force there is an equal and opposite force (some of these forces are negative) - this is basic physics my friend

QUOTE: The forward/backward speed of the conveyor will have no influence on the ability of the aircraft to gain airspeed and fly.

---- Of course it does. If the belt moves in the same direction it helps the plane, if it goes in reverse it hinders the plane!!

The plane cannot move forward unless it produces more power than that which the conveyor belt is taking away from it! By not moving forward there is no air to create the lift. Just think about it.

If the plane produces enough power to go 500mph on solid ground, then you take this plane and put it on a conveyor belt so it's wheels freewheel, it'll stay stationary relative to the ground!

again the plane CANNOT move forward.

Thank You.

ive tried explaining this time and time again but they cant understand

[MattF]

Oh good God. Slugsie, he's winding you up mate.

[dieselboy]

BTW, I mean static air,!

oh was it raining heavily on that humid summers day?


lol

[dieselboy]

Oh good God. Slugsie, he's winding you up mate.

i wasnt. until i wrote a bit about the lightning showers.

[MattF]

oh was it raining heavily on that humid summers day?

That would be statically charged air, where as static air, (even though that is technically never going to happen completely), is still air.

[Sancho]

Oh good God. Slugsie, he's winding you up mate.

I'm really not sure he is.

[MattF]

i wasnt. until i wrote a bit about the lightning showers.

Oh you had better be kidding. Seriously, if you're really arguing the point from conviction, I'm coming round there with the clue thrashing stick myself.

[MattF]

I'm really not sure he is.

Oh surely not? Do people like that truly exist?

[dieselboy]

That would be statically charged air, where as static air, (even though that is technically never going to happen completely), is still air.

lol i was kidding!

chill winston!

[Sancho]

The plane cannot move forward unless it produces more power than that which the conveyor belt is taking away from it! By not moving forward there is no air to create the lift.

But the power that the conveyor belt is taking away is only a tiny fraction of the thrust of the plane. If the plane is generating sufficient thrust to do 300mph on solid ground and the conveyor on which it stands is doing 300mph in the opposite direction, even if the friction on the wheel bearings is so great that 10% of the energy is cancelled out by the conveyor, you still have enough power to move forward at 270mph and take off.

[dieselboy]

Oh surely not? Do people like that truly exist?

people like what,
i made two valid points, because some people dont understand doesnt mean they are being wound up :/

[Snorkel]

sorry Diesel boy I edited my post, but you can see the changes luckily as you quoted me.

but I'll briefly repeat that you have to remember the question states the plane IS MOVING FORWARD.

If you're on the sideline, the plane is moving away from you at 10mph, and the conveyor is moving away (opposite) also at 10mph, the plane relative to the conveyor is travelling at 20mph. This 20mph is irrelevant - what matters is the 10mph that the plane is moving away from you. Change this speed to 500mph and the plane of course will take off (N.B it's wheels would be spinning at 100mph of course but only the 500mph matters to gt the lift).

sorry Slugsie.

[dieselboy]

But the power that the conveyor belt is taking away is only a tiny fraction of the thrust of the plane. If the plane is generating sufficient thrust to do 300mph on solid ground and the conveyor on which it stands is doing 300mph in the opposite direction, even if the friction on the wheel bearings is so great that 10% of the energy is cancelled out by the conveyor, you still have enough power to move forward at 270mph and take off.

that makes sense.

like i said a while ago, and someone else did a few mins ago;
if the plane has enough power to do 300mph on flat ground (taking away the wind resistance factor) then a conveyor going 300 mph the opposite way will stop it from going anywhere at all