Forums >Running 101>10K under 50 minutes... Please help
I've always wondered about this little mind bender. You are driving a car at 70mph on the interstate and you want to drive it up into the back of a trailer, itself being towed at, say, 69mph. When the car is driven into the trailer, does the driver have to radically let up on the gas in order to keep from zipping through the trailer at 70mph? Seems like the wheels of the car would have to slow down dramatically as they moved from the pavement to the trailer. Any advice on this would be helpful.
I've always wondered about this little mind bender.
You are driving a car at 70mph on the interstate and you want to drive it up into the back of a trailer, itself being towed at, say, 69mph. When the car is driven into the trailer, does the driver have to radically let up on the gas in order to keep from zipping through the trailer at 70mph? Seems like the wheels of the car would have to slow down dramatically as they moved from the pavement to the trailer.
Any advice on this would be helpful.
Once again, Mythbusters has you covered. Inertia or something.
mta: impressive, spaniel. You have these all bookmarked, don't you?
Runners run
Feeling the growl again
Google is a wonderful thing. That and a penchant for science shows.
Once again, Mythbusters has you covered. Inertia or something. mta: impressive, spaniel. You have these all bookmarked, don't you?
"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
#artbydmcbride
Is the plane on a treadmill indoors?
Prince of Fatness
Interesting that this was on the same page ... related videos.
http://www.youtube.com/watch?v=6YJ91FKZHI0
It appears that the term big rig ain't just about trucks.
Not at it at all.
Knight Rider - done that too.
That is cool.
I see you all have been having fun while I was out for my simulated treadmill standing-in-one-place-swinging-my-arms exercise.
So here's the deal. How exactly is the treadmill supposed to keep the plane stationary? The force delivered to the plane via the wheels has to match the engines' thrust. If the wheel bearings were frictionless, then it wouldn't matter how fast the treadmill went; no force would be imparted to the plane (the wheels would just spin faster and faster), and it would take off just fine. But here's the thing. The bearings do have some finite friction, but sliding frictional force is independent of velocity. So again, it doesn't matter how fast the treadmill is going, there is a (small) maximum force it can apply to the plane, which is easily overcome by the engines. So it will take off. Or, more properly, the question assumes an impossible treadmill.
Mikeymike's point about the treadmill possibly dragging enough air along to create lift is also a good one. Though the scenario doesn't arise, because the plane will move forward anyway, the implicit assumption is that the air is not moving. For an airplane-sized treadmill, that's probably realistic.
Best analysis I have seen is here.
Bottom line -- "Whoever asked this question is an idiot."
Super Pro Lurker
Personally I really enjoyed the xkcd analysis:
http://blog.xkcd.com/2008/09/09/the-goddamn-airplane-on-the-goddamn-treadmill/
I see you all have been having fun while I was out for my simulated treadmill standing-in-one-place-swinging-my-arms exercise. So here's the deal. How exactly is the treadmill supposed to keep the plane stationary? The force delivered to the plane via the wheels has to match the engines' thrust. If the wheel bearings were frictionless, then it wouldn't matter how fast the treadmill went; no force would be imparted to the plane (the wheels would just spin faster and faster), and it would take off just fine. But here's the thing. The bearings do have some finite friction, but sliding frictional force is independent of velocity. So again, it doesn't matter how fast the treadmill is going, there is a (small) maximum force it can apply to the plane, which is easily overcome by the engines. So it will take off. Or, more properly, the question assumes an impossible treadmill. Mikeymike's point about the treadmill possibly dragging enough air along to create lift is also a good one. Though the scenario doesn't arise, because the plane will move forward anyway, the implicit assumption is that the air is not moving. For an airplane-sized treadmill, that's probably realistic. Best analysis I have seen is here. Bottom line -- "Whoever asked this question is an idiot."
That was a great link!! I didn't even think of the wheels
Bacon Party!
Good grief! I can't believe "plane on a treadmill” came up or that there's anything to talk/think about.
Little plane: Prop "pulls" plane thru the air.
Stand on the same treadmill, wearing roller skates, and pull yourself hand-over-hand along a rope mounted to a stationary object in front of you -> you will move forward, treadmill be damned.
Liz
pace sera, sera
yeah, but that's not really roller skating. I mean come on.
Good grief! I can't believe "plane on a treadmill” came up or that there's anything to talk/think about. Little plane: Prop "pulls" plane thru the air. Stand on the same treadmill, wearing roller skates, and pull yourself hand-over-hand along a rope mounted to a stationary object in front of you -> you will move forward, treadmill be damned.
Well, I was wrong 2 out of 2 times on this thread, so I'm going running, but not on a treadmill, lest I want to go flying off
Maybe Mythbusters could do something with an Ostrich on a treadmill?
Age: 50 Weight: 224 Height: 6'3" (Goal weight 195)
Current PR's: Mara 3:14:36* (2017); HM 1:36:13 (2017); 10K 43:59 (2014); 5K 21:12 (2016)
Do you have empirical anecdotes to back up your bold assertion?
What;s the myth?
The energy efficiency of an American Princess walking at 7mph is less than either a Kenyan woman or an ostrich?
The process is the goal.
Men heap together the mistakes of their lives, and create a monster they call Destiny.
Why is it sideways?
Nice.