Will It Take off?

[OrionHunter]

OK, this is not necessarily an aircraft project related thread, but it is an interesting exploration of logic, physics, et.

Here is the problem:

A plane is standing on a runway that can move (some sort of conveyer belt). The plane moves in one direction, while the conveyer belt moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer belt to be exactly the same as that of the aircraft but in the opposite direction.

Can the plane take off?

Cheers!

 

[JAT BALWAN]

OK, this is not necessarily an aircraft project related thread, but it is an interesting exploration of logic, physics, et.

Here is the problem:

A plane is standing on a runway that can move (some sort of conveyer belt). The plane moves in one direction, while the conveyer belt moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer belt to be exactly the same as that of the aircraft but in the opposite direction.

Can the plane take off?

Cheers!

thm.... badam kha ke aata hun ruko...

 

[lem34]

OK, this is not necessarily an aircraft project related thread, but it is an interesting exploration of logic, physics, et.

Here is the problem:

A plane is standing on a runway that can move (some sort of conveyer belt). The plane moves in one direction, while the conveyer belt moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer belt to be exactly the same as that of the aircraft but in the opposite direction.

Can the plane take off?

Cheers!

Interesting. Am not a scientist but my gut feeling is it would. Might need downward force at a critical moment??

 

[Roybot]

Yes it will. Proof

 

[Skull and Bones]

OK, this is not necessarily an aircraft project related thread, but it is an interesting exploration of logic, physics, et.

Here is the problem:

A plane is standing on a runway that can move (some sort of conveyer belt). The plane moves in one direction, while the conveyer belt moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer belt to be exactly the same as that of the aircraft but in the opposite direction.

Can the plane take off?

Cheers!

Take-off depends on the lift generated by the wings, and lift depends on the relative wind velocity. And according to this problem, the plane is practically standstill wrt wind. So according to me, it won't.

I could be wrong though, coz' i'm into electronics, not aerodynamics.

 

[The HBS Guy]

No.

The conveyer is moving opposite to the direction of the plane.

The conveyer is negating whatever forward movement the plane is making.

Reduced (zero in this case) absolute speed of the plane has an adverse bearing on the wind speed over its wings.

The plane cannot generate enough lift.

The plane cannot take off.




Would be the opposite if the conveyor were to move in the same direction as the plane, though.

I could be wrong though, coz' i'm into electronics, not aerodynamics.

It's simple Newtonian physics. All engineers in India study that.

 

[Skull and Bones]

It's simple Newtonian physics. All engineers in India study that.

I know, maybe i didn't paid much attention to some irrelevant subjects. girls were very hot in our class, so you can't blame me either.

 

[Lone Shooter]

Well my thoughts were that it would not, cause the plane need opposite wind to help her get off, not the speed of rotating tires. In model plane it might work but in case of real planes I wont bet my money on it flying anywhere.

 

[JAT BALWAN]

I know, maybe i didn't paid much attention to some irrelevant subjects. girls were very hot in our class, so you can't blame me either.

bachpan se hi tharkee ho.....

 

[hunter_hunted]

No it will not . If I understand correctly coz my mind most of the time give me 'blue screen of death' when it comes to Physics qestions ,

even if the speed of plane is more than the opposite speed conveyor belt, We also have to consider Size and Weight of Plane and how much air is available under the wings.

 

[Lone Shooter]

Yes it will. Proof

Well that might not be a proof of anything meaningful.

You see the concept is that the speed of plane is same as that of the conveyer belt, hence the plane is practically static. In the case of the video you can see that the plane is actually moving, meaning its speed is more than that of the conveyer belt, hence false experiment in my view.

 

[OrionHunter]

Yes it will. Proof

But you haven't explained, WHY? That's the issue!!

So you're back to square one!

Cheers!

 

[longbrained]

It would fly. The reason is very simple. The plane does not need to move in relation to ground in order to get air born or remain in air. It just needs to be moving forward in relation to the air surrounding it. As the prop is providing that air, which is going around the wings, the plane will take off, with or without running on tarmac. The other scenario is like if there is a wind blowing against an aircraft on the ground and the wind speed matches the take off speed of the plane. Such a plane would become airborn too. In fact some planes have been destroyed this way in storms. All you need is the air move over the wings in fast enough velocity and the plane will get airborn.

 

[t_for_talli]

It works on bernoulli's principle.....velocity difference leads to pressure drop hence creating a lift (refer Bernoulli's eqn)

but in this case there is no velocity wrt the atmosphere around the plane (atmospheric envelop is stationary)
so the velocity term on LHS and RHS is zero resulting no pressure difference between the upper and lower surface of the wings => no upward force => no lift

But a lot depends on conveyor if it can move the atmospheric envelop with itself then calculations will definitely change

 

[Safriz]

no it wont fly..as due to conveyor belt mobin in.opposite direction the planecwill remain stationary and the wings wont generate any lift.