Airplane on a Conveyor conundrum

[dieselboy]

Picking up on Chillitt's point on the wings and engines usually going at the same speed....

The air comes out of the engines at 200mph, the engines are connected to the fuselage, the fuselage is connected to the wings and hence the wings go forward at 200mph. So the air is going over the wings at 200mph.

not necessarily

[BUSHWHACKER]

until what? the plane takes off?

To win the most drawn out thread trophy, currently held by MattF.

[Slugsie]

Picking up on Chillitt's point on the wings and engines usually going at the same speed....

The air comes out of the engines at 200mph, the engines are connected to the fuselage, the fuselage is connected to the wings and hence the wings go forward at 200mph. So the air is going over the wings at 200mph.

OK, this is probably going to just make matters worse but...

The air being pushed out of the back of an jet engine on an aircraft flying at 200mph airspeed is being pushed out at considerably more than 200mph.

Quick physics lesson...

The law of physics 'Every action has an equal an opposite reaction' takes into account not just speed, but also mass. So, if you weighed 100kg, and pushed a 10kg weight away from you, it pushes back. But because you weigh 10x as much it pushes back with 1/10th the force. So, if you push it away at 10kph, it will push you back at 1kph.

</lesson>

[Sancho]

not necessarily

Pretty much. If the engines and wings have a different airspeed you're going to have one or two problems.

[Sancho]

OK, this is probably going to just make matters worse but...

The air being pushed out of the back of an jet engine on an aircraft flying at 200mph airspeed is being pushed out at considerably more than 200mph.

Quick physics lesson...

The law of motion 'Every action has an equal an opposite reaction' takes into account not just speed, but also mass. So, if you weighed 100kg, and pushed a 10kg weight away from you, it pushes back. But because you weigh 10x as much it pushes back with 1/10th the force. So, if you push it away at 10kph, it will push you back at 1kph.

</lesson>

Yes, thanks, I knew that but I was trying to keep it simple for, um, someone else......

[Sancho]

To win the most drawn out thread trophy, currently held by MattF.

Was that the one about electrostatic speakers?

[Slugsie]

Does it make any difference if Tescos is also on the conveyor belt?

Only if Tescos is on the conveyor in front of the aircraft.

No idea what will happen when the aircraft gets to the scanner and the checkout person can't find the bar-code though.

[Slugsie]

Was that the one about electrostatic speakers?

Looking in the General forum, and ignoring the stickies threads, this one is #6:

http://www.hiluxsurf.co.uk/forums/fo...ort=replycount

[dieselboy]

OK, let's ignore the Tesco scenario, it just add complications that we simply don't need.

ok sorry

If airplane moves forward at 10mph. The conveyor moves backwards at 10mph. That is what the original statement said.
i agree
This means that they have a relative speed to each other of 20mph no matter how you measure it.
completely wrong. i say your wrong, because you state that the plane speed is measured by its ground speed. this is the speed its moving relative to the ground. if the conveyor is going the same speed as the plane but reverse or to put it another way -10mph, it will be going the same speed as the ground.

10mph + -10mph = 0mph,

but the plane isnt stationary is it, its moving forwards at 10mph as measured by the ground. this means the conveyor is stationary with the ground.

No ifs, no buts, that is what happens. no it dont :P Given that the conveyor, acting through the free spinning wheels, dont mention the wheels, its not important here cannot excerpt any significant force on the aircraft, then the conveyor will in no way impede the forward motion of the aircraft. blah

The only way that the aircraft cannot fly is if someone can explain how the conveyor, acting through free spinning wheels, can excerpt a force on the airframe.
WAHT! (i turned german) i explained this earlier!!! but this isnt what is happening.
Until someone can explain that, all other arguments are mute.

ive explained it :/

[logey79]

To win the most drawn out thread trophy, currently held by MattF.

he's a boring b'stard isn't he, what thread was that then?

[nero279]

"Triple XXX men" or "electric fans"?

[dieselboy]

OK, this is probably going to just make matters worse but... doubt it

The air being pushed out of the back of an jet engine on an aircraft flying at 200mph airspeed is being pushed out at considerably more than 200mph.

yes but the forced produced is only enough to keep the plane at 200mph, or else it would accellerate

Quick physics lesson...

The law of physics 'Every action has an equal an opposite reaction' takes into account not just speed, but also mass. So, if you weighed 100kg, and pushed a 10kg weight away from you, it pushes back. But because you weigh 10x as much it pushes back with 1/10th the force. So, if you push it away at 10kph, it will push you back at 1kph.

but this doesnt help you understand that this is a trick question, and that the ground and the conveyor belt both move away from the plane at the same speed the plane is moving away from them, except only the opposite direction.

</lesson>

[dieselboy]

he's a boring b'stard isn't he, what thread was that then?

i can feel the grey hairs coming out

[nero279]

he's a boring b'stard isn't he, what thread was that then?

"Triple XXX men" or "electric fans"?

To win the most drawn out thread trophy, currently held by MattF.

Woo hoo! only 6 more pages to go!

http://www.hiluxsurf.co.uk/forums/sh...ad.php?t=24232

[nero279]

but this doesnt help you understand that this is a trick question, and that the ground and the conveyor belt both move away from the plane at the same speed the plane is moving away from them, except only the opposite direction.

eh?