A harmless little riddle

[quote]Engineer wrote:

because in order for the wheels speed to be the same speed as the treadmill you can have no force coming from the plane which means it is not on. [\quote]

That is wrong. You need thrust from the engine of the plane to keep the plane "stationary" relative to the ground. There must be a force from the plane to overcome rolling resistance and friction to get the wheels rolling in the first place.

Asterix wrote:

Why do we have to assume the movement is relative to the air?

Because that's how airplane speeds are measured.

That is wrong. You need thrust from the engine of the plane to keep the plane "stationary" relative to the ground. There must be a force from the plane to overcome rolling resistance and friction to get the wheels rolling in the first place.

no that is wrong because then the wheels would be spinning faster than the treadmill which was the question in hand.

Engineer wrote:

That is wrong. You need thrust from the engine of the plane to keep the plane "stationary" relative to the ground. There must be a force from the plane to overcome rolling resistance and friction to get the wheels rolling in the first place.

no that is wrong because then the wheels would be spinning faster than the treadmill which was the question in hand.

I think you're thinking of "ideal" wheels or something. If you turn a treadmill on with a skateboard on it, it will roll off the back of the treadmill. You must apply some force to keep it from rolling off the back and to spin the wheels up to the speed of the treadmill. This is the force required from the plane engines in order to keep the plane sitting stationary on the treadmill as the treadmill accelerates. Then, after the treadmill is matching the speed of the wheels, you still need a force to keep the airplane sitting there, but it's much smaller and has used to counter the internal friction of the wheel.

That is wrong. You need thrust from the engine of the plane to keep the plane "stationary" relative to the ground. There must be a force from the plane to overcome rolling resistance and friction to get the wheels rolling in the first place.

by the way there is no real point where the plane will ever be staionary for a significant amount of time. because the planes engines will always exert X amount of force while the treadmill will only beable to put a percentage of that same force onto the plane in the opposing direction and the plane will always be moving forward, once it is started.

Last part of my message should read,

"Then, after the treadmill is matching the speed of the wheels, you still need a force to keep the airplane sitting there, but it's much smaller and is used to counter the internal friction of the wheel."

yes i am thinking of ideal wheels. do you know why people usually use ideal thoughts, to make things less complicated. yes you are correct in what you are saying knowitall, but that amount of force is insignificant and can be neglected in the bigger picture which is why we have "ideal" things such as these ideal wheels on our plane.

Pherekydes wrote:

Because that's how airplane speeds are measured.

Sometimes 'airspeed' is reported. Other times 'groundspeed' is reported.

Where, in the original post, is it specified we are dealing with airspeed or groundspeed?

Given that the plane is sitting on the treadmill and there is no mention of airflow, wouldn't it be assumed that the 'speed of the plane' is either relative to the treadmill or relative to the rest of the world?

Engineer wrote:

without that FORWARD(theres that word again) thrust there would be no vertical component now would there. so it is safe to assume that the thurst does have an effect on the vertical component

god, you are dense. that has been my point this whole time. you think that the wheels of the plane are freely spun by the treadmill beneath them. that is not the case. in order for that to happen you need to take the weight off the wheels. that doesn't occure unless we have lift, which requires AIRSPEED. and since the wheels are not going to be freely spun at the start, they will act just the same as they would on a normal runway. and since the treadmill matches the speed of the plane, no airspeed is built up, no lift occurs, and the wheels do not spin any faster than the plane is moving. you are wrong if you think anything else would happen in this situation.

you know it's amazing that so many people can convince themselves that false information is true. but then again, the "majority" of the country elected bush... twice. oops, did i say something that is going to end our wonderful thread? sorry in advance if i did.

hahahaa no you proved that you are more of a troll than ever. give up the wheel thing with it cant spin faster than the plane is going. you sir need to strap on your special helmet and take your place cause you have no idea whatyou are talking about.

"they will act just the same as they would on a normal runway"

you said this and i believe it is true, the wheels will act as they do on a normal run way as the plane moves forward normally in real life. and what happens on normal runways pal? PLANES TAKE OFF thats what happens. LOL

Engineer wrote:

hahahaa no you proved that you are more of a troll than ever. give up the wheel thing with it cant spin faster than the plane is going. you sir need to strap on your special helmet and take your place cause you have no idea whatyou are talking about.

"they will act just the same as they would on a normal runway"

you said this and i believe it is true, the wheels will act as they do on a normal run way as the plane moves forward normally in real life. and what happens on normal runways pal? PLANES TAKE OFF thats what happens. LOL

Quit picking on "wow." Everyone thinks he is a moron. You continue to reply to his posts just to make yourself feel better. Meanwhile, you're getting owned by the others.

well you are right on the first account. but i am getting owned by the others? didnt you say i was right but then asked if i saw it another way and i simply said no. only and a$$clown could see it the other way

ok, now i see... you're the kind of engineer that drives trains. that makes a little more sense.

normal runways aren't moving, pal. if you can't comprehend that a treadmill moves things backward, then i can't help you. i award you no points, and may god have mercy on your soul.

Why does interpreting a question in a different, valid way qualify a person as being an assclown?

wow. wrote:

ok, now i see... you're the kind of engineer that drives trains. that makes a little more sense.

normal runways aren't moving, pal. if you can't comprehend that a treadmill moves things backward, then i can't help you. i award you no points, and may god have mercy on your soul.

Dude, seriously, shut the f*** up. Everyone, no matter if you think the f***ing plane will fly or not, thinks you are an idiot.

So shut the f*** up.

because its not very valid if you know how to read? thats why

ok, sorry. my bad. i guess i'll listen to your censored swearing and stop posting cause you know, you sound really scary and all. why don't you shut the f*** up and post something that may be of some use in the conversation you little bitch.

i've been trying to demonstrate the correct outcome and it's not my fault if you don't want to admit that you and your shit for brains online buddies are wrong. but hey, i guess it's better that you amuse yourself with your skewed perception of reality on an internet message board than actually f*** shit up in the real world.

i'm now going to leave this thread, like all the other sane, rational people already did. have fun discussing how right you are with yourselves and congratulating each other on how you got rid of that idiot wow. maybe you can get a little circle jerk going while you're at it.

hahahahhaaha this stuff is hilarious, all over a plane flying or not flying off of a treadmill.

Why isn't it valid?