Forums >Running 101>10K under 50 minutes... Please help
#artbydmcbride
Personally I really enjoyed the xkcd analysis: http://blog.xkcd.com/2008/09/09/the-goddamn-airplane-on-the-goddamn-treadmill/
Personally I really enjoyed the xkcd analysis:
http://blog.xkcd.com/2008/09/09/the-goddamn-airplane-on-the-goddamn-treadmill/
Runners run
Best analysis I have seen is here. Bottom line -- "Whoever asked this question is an idiot."
Best analysis I have seen is here.
Bottom line -- "Whoever asked this question is an idiot."
That is a good analysis and totally makes sense. And our legs and feet are not frictionless wheels so we are running on a treadmill?!
Why is it sideways?
When I think about this, it seems totally obvious to me that the plane would take off, as the jet propulsion would create force that would push the plan forward.
The backwards-moving treadmill would create practically no force opposing that force, as it is just spinning the wheels. If those forces were equal, such that the plane could not accelerate, dynamic equilibrium would mean having a treadmill able to apply a force to free spinning wheels that was equal and opposite in magnitude to a jet engine, which would obviously be mechanically impossible since the inertia of those wheels is so small.
Such a treadmill could never be built, so on any real-life treadmill the plane will take off, or at the very least you'd have to make all sorts of other physically impossible assumptions that would lead to the possibility of such a treadmill existing.
not bad for mile 25
When I think about this, it seems totally obvious to me that the plane would take off, as the jet propulsion would create force that would push the plan forward. The backwards-moving treadmill would create practically no force opposing that force, as it is just spinning the wheels. If those forces were equal, such that the plane could not accelerate, dynamic equilibrium would mean having a treadmill able to apply a force to free spinning wheels that was equal and opposite in magnitude to a jet engine, which would obviously be mechanically impossible since the inertia of those wheels is so small. Such a treadmill could never be built, so on any real-life treadmill the plane will take off, or at the very least you'd have to make all sorts of other physically impossible assumptions that would lead to the possibility of such a treadmill existing.
I think it's even simpler than that. It just takes off with its wheels spinning about twice as fast as they normally would. Building the treadmill would be difficult.
Now, ready to talk about landing on a treadmill?
Maybe this is a dumb question but are we imagining a treadmill out of proportion in length relative to a person on a normal treadmill? In other words, it would require a runway of sorts, correct? That is what I understood from that analysis and I guess where some confusion might lie. Not trying to be dense here, but that does make things simpler.
Such a treadmill could never be built
But if it could, spaniel would find a way to break it.
Dave
Bacon Party!
Yes, a treadmill the same length as runway required for a given plane to take off in given conditions.
Liz
pace sera, sera
What about a helicopter?
Feeling the growl again
Damn straight. Hahaha, I love it.
"If you want to be a bad a$s, then do what a bad a$s does. There's your pep talk for today. Go Run." -- Slo_Hand
I am spaniel - Crusher of Treadmills
The whole plane thing is just a stupid semantics trick. The question is worded to make you thing that the plane is stationary relative to everything but the belt.
Here's a better question: If I am running on a treadmill and start at the extreme back of the belt and move very, very slowly to the extreme front of the belt by the end of my workout, am I running?
Wheresmymule, that's a damn good question. I might have to think about that one, but i have a better question. How many of you ladies like ice cream, OR frozen yogurt? Well, just so happens that the Hartford marathon was a bust 'cause of the rain. I couldn't set up my Tootsie pop stand. So, now my buddy and i are going to set up an ice cream stand at the NYC marathon and the same courtesy will be extended to the ladies as the tootsie pop. We're going to give out FREE ice cream cones to the ladies, only thing is, you need to eat them right there at the stand. So hope to actualy get meet some of you guys on Sunday, bring your appetite. Cheers.
OK then. All this thread is missing now is sportjester.
His more mild-mannered close relative started this whole mess.
Be careful what you ask for.