Andrew
Club Member
I can't believe how much of a problem this causes in people's minds. A theoretical or real plane in this situation would take off.
http://www.straightdope.com/columns/060203.html
http://www.straightdope.com/columns/060303.html
The skateboard analogy is totally correct. Some of the greatest minds in physics have been asked this at lectures and all of them have answered it will take off - there is absolutely no doubt.
http://www.straightdope.com/columns/060203.html
http://www.straightdope.com/columns/060303.html
The skateboard analogy is totally correct. Some of the greatest minds in physics have been asked this at lectures and all of them have answered it will take off - there is absolutely no doubt.
N
nizzanz1
Guest
would be to increase the force of the acceleration of the conveyor and be constant acceleration to give the force. not just by only matching in speed/acceleration what the plane is doing. but the puzzle does not allow for that to happen.
Antony
Ex. Club Member
right then, a level physics guy coming through.
took me 10 minutes to think of this...
the answer is yes.
lets think about this for a second...
if you were to take the wheels off the plane and accelerate the plane to take off speed.... then add some wheels to it.... and place it on a moving runway at exactly the same seed as the wheels are doing.... wouldnt this be the scenario we have whilst taking off as normal
or on a stationary runway... or even landing... the runway is moving in the opposite direction at ecxatly the same speed as the plane as its conected to the earth...... and the planes doing 300mph+
for all you boffins out there... the resistance of the wheels on the conveyor, "if you will" will allways be less than the thrust from the engines... as the plane is still stationary to the air flow arround it and the eath its in, the plane will move forwards... the thrust is acting on a freewheeling body by pushing or thrusting against air density around the object. again, there would be friction from the wheels, but enough to stop a 20,000lbs thrust plane from taking off.... i dont think so.
theres also the matter of the elastic band powered plane i just put on my uncles treadmill..... if you measure the static speed of the plane, its still static, stationary. if you have any force pushing against it, i-e "thrust" it will move in what ever way there is no resistance.... i-e the fore vector. in other words... lol.....einstien..... every action has an equal and opposite reaction..... if you thrust upon something, unless there is an equal thrust in the opposite direction, then there will be movement......there is no airflow whilst its stood still, but as the jet engine works on air flow, or creating it, there will be an inbalance untill the plane moves as fast as the gasses from the plane....indeed creating flight.
buyeah!:laugh: :laugh:
thus my plane moved off my uncles treadmill...... and that should be the end!
took me 10 minutes to think of this...
the answer is yes.
lets think about this for a second...
if you were to take the wheels off the plane and accelerate the plane to take off speed.... then add some wheels to it.... and place it on a moving runway at exactly the same seed as the wheels are doing.... wouldnt this be the scenario we have whilst taking off as normal
or on a stationary runway... or even landing... the runway is moving in the opposite direction at ecxatly the same speed as the plane as its conected to the earth...... and the planes doing 300mph+
for all you boffins out there... the resistance of the wheels on the conveyor, "if you will" will allways be less than the thrust from the engines... as the plane is still stationary to the air flow arround it and the eath its in, the plane will move forwards... the thrust is acting on a freewheeling body by pushing or thrusting against air density around the object. again, there would be friction from the wheels, but enough to stop a 20,000lbs thrust plane from taking off.... i dont think so.
theres also the matter of the elastic band powered plane i just put on my uncles treadmill..... if you measure the static speed of the plane, its still static, stationary. if you have any force pushing against it, i-e "thrust" it will move in what ever way there is no resistance.... i-e the fore vector. in other words... lol.....einstien..... every action has an equal and opposite reaction..... if you thrust upon something, unless there is an equal thrust in the opposite direction, then there will be movement......there is no airflow whilst its stood still, but as the jet engine works on air flow, or creating it, there will be an inbalance untill the plane moves as fast as the gasses from the plane....indeed creating flight.
buyeah!:laugh: :laugh:
thus my plane moved off my uncles treadmill...... and that should be the end!
Alienfish360
Awesome Dawson
if you put it on the conveyor. And don't have anything running, as the wheels are free rolling. It will NOT move. as the wheels will just spin with the conveyor.
When you add thrust, it will take the plane forwards as you have now unbalanced the forces
When you add thrust, it will take the plane forwards as you have now unbalanced the forces
C
CAT 20T
Guest
LOL
Love the explanation on that link - proof you shouldn't believe everything you read.
The conveyor has no affect on the plane other than to spin the wheels twice as fast as they'd be rolling if it was on solid ground.
You could drive your car on a conveyor that tracked your speed, you'd just be driving twice as fast to reach a given speed
Love the explanation on that link - proof you shouldn't believe everything you read.
The conveyor has no affect on the plane other than to spin the wheels twice as fast as they'd be rolling if it was on solid ground.
You could drive your car on a conveyor that tracked your speed, you'd just be driving twice as fast to reach a given speed
Batch
Ex. Club Member
if you put a car on a conveyor and started the conveyor the car would move in the same direction as the conveyor, the wheels would turn in the opposite direction and the car would not move as fast as the conveyor but it would still move in the direction of the conveyor...
...if the car weighed nothing then it would stay stationary and the wheels would free rotate at the same speed as the conveyor,as because the car weighs nothing there would be no force creating friction on the conveyor surface.. all about weight (or mass) and forces.
essentially the plane would do the same but the force of the engines pulling the plane forward through the air would overcome the downwards force of the friction of the tyres on the conveyor and pull the plane forward (wheels still turning in the opposite direction)...
at least i'm pretty sure (but it is half 11 and past my bed time) please correct me if i'm wrong?
...if the car weighed nothing then it would stay stationary and the wheels would free rotate at the same speed as the conveyor,as because the car weighs nothing there would be no force creating friction on the conveyor surface.. all about weight (or mass) and forces.
essentially the plane would do the same but the force of the engines pulling the plane forward through the air would overcome the downwards force of the friction of the tyres on the conveyor and pull the plane forward (wheels still turning in the opposite direction)...
at least i'm pretty sure (but it is half 11 and past my bed time) please correct me if i'm wrong?
Krian
Fear me, for I am Onibaku
:doh: Just realised, with the wheels free rotating then the wheels would move as fast as the conveyor, then move faster as the plane's engine pulled it forwards... the conveyor would speed up but the plane would still move faster.. so it could take off 
K, I admit it, I was wrong :blush:
On the flip side, if the conveyor didn't have a finite speed the I reckon the wheels would pretty quickly overheat and blow, so the plane wouldn't really go anywhere :laugh:
K, I admit it, I was wrong :blush:
On the flip side, if the conveyor didn't have a finite speed the I reckon the wheels would pretty quickly overheat and blow, so the plane wouldn't really go anywhere :laugh:
N
nizzanz1
Guest
Krian said::doh: Just realised, with the wheels free rotating then the wheels would move as fast as the conveyor, then move faster as the plane's engine pulled it forwards... the conveyor would speed up but the plane would still move faster.. so it could take off
K, I admit it, I was wrong :blush:
On the flip side, if the conveyor didn't have a finite speed the I reckon the wheels would pretty quickly overheat and blow, so the plane wouldn't really go anywhere :laugh:
thats not right. the plane only needs 60mph air speed to take off (prop 2 seater). or i think 180mph for a big jet liner. the conveyor maximum speed would be equal to the take off speed of the plane. the wheel speed (i think?) would be only double the take off speed. which the wheels can easily cope with. its got nothing to do with how fast the conveyor can go to infinite speeds.
OP
OP
RIK
Guest
Dusk said:Anymore rik?
nope..just this one i spotted
