Physics Puzzle

[Softus]

If the brakes were on then the wheels wouldn't rotate, so the conveyor wouldn't start, so wouldn't the plane push the conveyor forward and then take off?

 

[Softus]

Aim sorry, ai ave a coawld.

 

[xerxes]

If the brakes were on, I assume the rubber would burn off the tyres. The plane would take off but have difficulty landing.

 

[WDIK]

If the brakes were on then the wheels wouldnt rotate, so the conveyor wouldnt start, so wouldnt the plane push the conveyor forward and then take off?

no there is no rotational force from the wheels they are pacisve

 

[WDIK]

typo

 

[Softus]

no there is no rotational force from the wheels they are pacisve

Do you mean that they're conscientious objectors?

 

[WDIK]

no i mean the wheels are not involved in any element of propulsive force they are facillitators and do not react except as a consequence.
they are not in direct contact with either object of propulsive force.

 

[Softus]

But don't the tyres go squish and the bearings go rubbity rub?

 

[xerxes]

Too technical for me.

I concede there must be some energy losses through the wheels. But I dont think theyre significant.

 

[Softus]

What if there was a REALLY strong headwind?

 

[WDIK]

Dont think this ones been posted here before.

An aircraft is standing on a very long runway that can move (a conveyor belt). The aircraft moves in one direction, while the conveyor belt moves in the opposite direction. This conveyor belt has a control system that tracks the aircrafts wheels speed and tunes the speed of the conveyor belt to be exactly the same as the wheels, but in the opposite direction. There is no wind. The pilot begins to add thrust to the engines...

Will the plane ever take off?

 

[xerxes]

Now youre changing the rules. The original question specified no wind.

Presumably a sufficiently strong headwind could counteract the thrust of the engines. On the other hand, does it also contribute to lifting the aircraft?

 

[Softus]

Now youre changing the rules. The original question specified no wind.

I was lying then. Which reminds me...

What's green with huge wheels?

 

[xerxes]

I dont know ...

 

[Softus]

Grass.