Long rod question
- Thread starter moon man
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Difference is, you're being driven by the friction of your shoes (or feet) against the treadmill.
The plane is being driven by the thrust of the jets, so it will still move forwards and get air flowing over the wings.
The wheels don't power the plane.
Ah, this was my initial assumption, and so diamond would be the fastest possible? Still far slower than either light or electricity though so this instant movement only exists in theory!
But if you were on a treadmill on rollerskates and you did an uber fart then you'd move forwards - assuming the force of your fart was in excess of the frictional force in the bearings of the wheels - and you'd crash into the computer at the front of the treadmill and look a right berk.
ahhh that is the mistake people make
you have to realise that there is no possible way that a treadmill could ever negate the forward motion of the plane (unless the brakes where on)
imagine standing on a treadmill on roller skates.
Soldato
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The propeller pulls against the air, not against the ground.
Basically the prop starts up, the prop starts tugging the plane forward, the treadmill starts spinning to match, but the only difference that makes is that the wheels rotate twice as fast as you'd normally expect.
The engine keeps ramping up the power, the plabne gets faster, and away up shes goes. Only difference is that the wheel bearings have got slightly hotter than usual.
Heh, I'm waaaay ahead of you there.
Yes.............................. we got a decent answer /thread
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You've just described a different scenario to the experiment in question. In your case you're moving forward faster than the conveyor belt is moving backwards
But you will move relative to the air, because the force of the jets/props will pull you forward harder than the friction in the wheels will hold you back.
It doesn't matter. The wheels will pick up the slack by spinning fast enough to make up the difference between how fast the treadmill is going backwards as the plane goes forward.
course it makes a bloomin difference
the jets/props push air backwards which propel the plane forwards
your legs/shoes push road backwards which propel you forwards.
when the treadmill starts you have to fight the force of it if your on foot
if your on wheels on the treadmill like a plane then you wont move
But in this thought experiment if the treadmills were not the little ones you are imagining but very big ones, AND, if their only purpose was to negate the forward motion of the plane caused by the plane being pushed along the ground by it's engines then plane never would move, never would travel off the end of the treadmill an never would happily charge down the runway and soar into the air.
Yes, this is fact it can't really be discussed. The only situation where this wouldn't happen is if the wheels brakes were on but in this case the plane would neither move on a runway or a treadmill of matched speed! This is the very essence of brakes! Bear in mind in reality the brakes may be overcome by engine thrust, I have no idea, but irrespective it makes no odds if it's on a treadmill or not.
At no point does the original riddle say the plane stays relavent in position to the treadmill.
The treadmill runs backwards at the same speed the plane moves forwards (the wheels therefore spin at double the speed the plane is moving)
The plane takes off.
a treadmill CAN NOT negate the forward motion of a plane. never . ever.
explain how it could ?
I was imagining something along the lines of a powered treadmill and motion sensors - not a static unpowered thing.
even if it was powered and travelling at 10 gazillion revs per minute it wouldnt stop the plane taking off (if you assume frictionless bearings in the wheels)
you basically have to ignore the wheels because all theyre are used for is to stop it scraping the tarmac. and to slow it down when taxi ing
just look at seaplanes
you basically have to ignore the wheels because all theyre are used for is to stop it scraping the tarmac. and to slow it down when taxi ing
just look at seaplanes