Yep, its all how you interpret the question.
We need an attorney to further define the question.
Plane on a Treadmill
- Thread starter Warder60
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Yep, its all how you interpret the question.
We need an attorney to further define the question.
No, the problem says it matches the planes speed, it doesn't say "the treadmill is moving at the speed needed to keep the plane motionless". This is not semantics here, this is just simple reading comprehension.
The plane is going X mph forward, the treadmill is going X mph in the opposite direction. Nowhere does it say the treadmill is ever going any faster than the plane.
Yep, its all how you interpret the question.
We need an attorney to further define the question.
Yep - and since there are very few treadmills designed for aircraft
eek I think most of us would interpret the question as to the common purpose of a treadmill - that being the prevention of forward motion.It's sort of a common sense thing, isn't it? :wink:
I don't think it was trying to be bad. It was a B-list movie (Samuel L. being the exception, and he did it because it sounded funny). I went in expecting nothing, and was thoroughly amused.
I dunno but it's a darn good thing for them that they changed the name back to "Snakes on a Plane" (insted of Flight ###), and that they went back and edited in Samuel L. Jackson saying "I'm tired of these mother ****ing snakes on this mother ****ing plane"
Otherwise the movie would have been a complete bust
Nope, it says it is going the same speed. Not faster, not slower, the same speed. If the treadmill moved faster, it would make the plane go backwards.
How are you determining the speed of the treadmill then?
Slower treadmill, plane moves forward.
Faster treadmill, plane moves backward.
Equal speeds, no movement.
That would be why I said the plane is going X mph and the treadmill is going X mph, X = X last I checked, so it's the same.
That's not how a treadmill works in this case, stop thinking of a treadmill like you're running on it. The problem says, as I quoted, the treadmill is capable of accellerating to MATCH THE SPEED OF THE PLANE. MATCH = EQUAL = SAME
Assuming friction is negligible, which we can assume it is, as the treadmill moved faster, the only difference would be that the wheels of the plane would rotate faster to keep up. This would have very little affect on the overall speed of the aircraft. So it doesn't matter if the treadmill is moving 0mph, or equal to the plane or faster or slower than the plane, the only thing that would really be affected is the rotation of the wheels.
Let's say the jet engines would propel the jet at a constant rate of 10 mph on flat ground. The question becomes, what would happen if we now set this plane on a treadmill set at 10 mph in the opposite direction? The result is... the plane would still travel forward at 10 mph in relation to the ground, but the wheels would be turning at a relative rate of 20 mph.
Stop your voodoo math! Obviously the plane would go 88 mph in reverse and consequently go back in time. Physics people.
Seriously though, this question isn't really all that hard once you stop getting hung up on the treadmill.
I agree with this, but I am not convinced that this is the intent of the question. Maybe it is, maybe it isn't. It is all interpretation. Is the "matching of speeds" relative to the plane to the ground, or the plane to the treadmill?
It is exactly the same as running on a treadmill. Instead of the planes engines counteracting the forces of the treadmill, the person is applying the force by running. The physics behind it is exactly the same. The only difference is the scale of power. If it isn't, please tell me how the laws of physics apply differently to people than airplanes.
Imagine a car on a treadmill, with a string attached to it, and you holding the string a the front of the treadmill.
When you start the treadmill, the cars wheels will accelerate to the speed of the treadmill because you are holding the string... You don't have to pull the string at the speed of the treadmill to move the car forward, you only have to overcome a TINY amount of friction between the wheels and the treadmill...
ANY airplanes engines can accomplish this quite easily.
As stated in the link to the STRAIGHT DOPE... imagine a plane on a frozen lake... The plane moves forward because of THRUST... not because its wheels spin forward.
When you start the treadmill, the cars wheels will accelerate to the speed of the treadmill because you are holding the string... You don't have to pull the string at the speed of the treadmill to move the car forward, you only have to overcome a TINY amount of friction between the wheels and the treadmill...
ANY airplanes engines can accomplish this quite easily.
As stated in the link to the STRAIGHT DOPE... imagine a plane on a frozen lake... The plane moves forward because of THRUST... not because its wheels spin forward.
I seriously cannot beleive that this question has been debated on here this long.
If the treadmill speed MATCHES the speed the plane is going, the plane IS NOT moving relative to the ground. IT IS JUST SPINNING ITS WHEELS. The forward movement is what creates lift. The engines themselves DO NOT create lift--causing air to flow around the wings does (otherwise, how would a glider work? It has no engine).
I think I am stupider for reading this thread (note that I would have said more stupid before reading this thread).
If the treadmill speed MATCHES the speed the plane is going, the plane IS NOT moving relative to the ground. IT IS JUST SPINNING ITS WHEELS. The forward movement is what creates lift. The engines themselves DO NOT create lift--causing air to flow around the wings does (otherwise, how would a glider work? It has no engine).
I think I am stupider for reading this thread (note that I would have said more stupid before reading this thread).
In the string example, you are applying the force, or whatever the string is attached to. What happens if you remove that force by releasing the string? Its all the same physically speaking. Runner, string, or airplane engine, there are forces at work. The string example is a static force, where the runner and engines are dynamic forces.
As far as the STRAIGHT DOPE example, we know the planes wheels do not do any driving. Thats irrelevant. Wheels are just a tool to minimize friction. I'd guess most modern jet airplanes have the power to take off on a paved runway if even you replaced the wheels with skids.
In that example, the string would be the force of the engines. Removing the force/letting go of the string would be like shutting the engines down.
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