ArkansasRam

oh boy don't we lead a dull life

Geico266

Beam, at least the "rocket scientists" who responded before you could read. There is no need for derogitory remarks towards others, all that does is stiffle creative thought. This is a thinking person's thread.

Rammtuff said it best..... we need more beer.

rvnagain

The speed of the wheels have nothing to do with air speed. Sure the plane will take off.

If the dozer is going 5 mph forward and the top track is going 10 mph, the bottom track will be going 0 mph.

derek840378

owww my head hurts!!! but here's what i got. lets say the plane has no thrust, the plane moves backwards. now fire the engines and the plane is stationary. No forward momentum, no air, no lift

now for the second one, the bottom of the tracks dont move

Begle1

Oh, I get it now...

The air plane's wheels don't have any power going to them do they? So it's not like a dyno...

I change my answer. The plane will take off. D'oh...

derek840378

no! the conveyor is pushing the plane backwards! it can never move, there will be no wind! the belt goes <----- way just as fast as the plane "tries" to go -----> way. they equal out to 0. go read einsteins theory of relativitey. it will help.

JKM

I think the plane will take off , but i am here to contest the bulldozer question...

If the dozer is going 5 mph , the bottom of the track is going 0 , and the top is going 10 , IN RELATION TO THE GROUND, if you relate it to the dozer itself , the top of the track is going 5 , and the bottom is going 5

rvnagain

Stand next to the track of the doser the part of the track on the ground is not moving.

pmtg

THE PLANE WILL TAKE OFF!!!

frozen/snowy regions use ski's instead of wheels/tires. a float plane has floats and no wheels/tires. how do the ski's or floats accelerate the plane? they DONT! the propeller/impeller spins creating a low pressure zone in the AIR in front of it and the resultant force accelerates the plane forward. similiar design used for the wing is used for the propeller/impeller; to increase the speed of the air on one side but not the other. BERNOULLI's is all you need for this one...

will the wheel bearings survive just at takeoff? dont know on that one...

on a side note, you can actually land a float plane on the ground without destruction; you could take off from the ground with a float plane if it had enough power to overcome the drag. so if you had a big enough engine to overcome the drag of the floats on the ground, you could take off; and since there would be no wheels/tires spinning, the conveyor would never activate.

kcatsun,
the speed of the track in relation to the dozer is 5mph one way, and negative 5mph the other depending on your coordinate system sorry, thought i'd be a smart donkey

derek840378

YES I'M YELLING! IMAGINE TRYING TO SWIM UPSTREAM IN A RIVER, IF YOU MATCH THE SPEED OF THE RIVER, U WONT BE GOING ANYWHERE. lets see if that changes some of your minds

Begle1

The wheels on the airplane eliminate friction between the ground and the craft.


As the airplane's jet engines create thrust, the airplane will move forward. The wheels are attached to the airplane, so the wheels as well will move forward. The airplane doesn't have to overcome the conveyer belt.

The point of the puzzle is that despite the conveyer belt, the plane will move forward. While a stationary plane will not take off, there is no way the conveyer will hold the plane stationary. So the plane will take off, provided that it can overcome the axle's friction, which shouldn't be factored into the equation.

Swimming upstream in a river would be like the airplane taking off in a very strong headwind. A better analogy would be to strap a rocket on your back, put on roller skates, and then get on a tread mill... No matter how fast the treadmill is moving backwards, the rocket will move forwards because the rollor blades remove the friction between you and the belt.

Another analogy would be to take a rolling pin and hold it on a conveyor belt. You can turn the conveyor belt on as fast as you want, but no matter how fast it is moving you can always roll the rolling pin forward on the conveyer belt with the same amount of force. The only difference is that the pin will be rotating faster as the belt moves faster, but the same amount of "thrust" will always move the pin forward the same distance.


I was initially wrong because I was thinking that the airplane's engines were moving the jet's wheels, which is obviously wrong.

derek840378

impossible. put the plane on the conveyor, engines off. start the conveyor and the plane will move backwards w/ the belt. there is no such thing as eliminating friction.

plus, no matter how fast the (unpowered) tires turn the belt will move just as fast. if the tires are moving at 300 mph, so will the belt rendering the plane motionless.

the rolling pin theory is null because you would be able to move on the solid ground, the engines arent "holding on" to the air.

the big thing to think about is the wheel speed. the plane can never advance due to this little detail. if the plane does advance the belt will speed up to match it er go no forward progress.

hotdram

Before I answer this,
I have to know, is this taking place in the northern or southern hemisphere?

~Rob

derek840378

i wonder how supreme court justice roberts would avoid this one!

pmtg

nope. your hand/feet and water in the river are analogous to the propeller/impeller and AIR.

i honestly think you are just playing with us now. you seriously cant believe the plane wont take off.



***edit: a float plane can take off whether its going with or against the current.

im done with this thread.