Skill's weekend teaser

[megamuel]

Its doing the same thing as a conveyor belt is it not? Material being pulled over a surface - just like a conveyor belt/treadmill. Only difference is that its not 1 continuous loop. The point is, the truck and conveyor belt could be doing 200mph in the opposite direction, the propeller still pushes the plane forward.

Sam.

P.S. Sorry about my English!

 

[Mr. Charts]

I must be crazy to have spent any of my life reading this thread.
I mean, what would happen in an impossible and ill-defined scenario?
That's something to read hundreds of posts about?
I really must have been crazy.

So, I'm out of here by a much more probable form of air transport.

 

[TheBramble]

I'm too busy to spend 20 pages explaining it to you. I was just explaining it for the other guy. By the way, I didn't say the plane moves faster than the runway. The runway matches the speed of the plane. So when the plane goes faster (because its engines are pushing it), the runway goes faster in the opposite direction. All that means is that the wheels are spinning twice as fast than they would normally when the plane takes off.

I am genuinely impressed. You are truly special.

 

[megamuel]

Thank you

 

[Atilla]

Its doing the same thing as a conveyor belt is it not? Material being pulled over a surface - just like a conveyor belt/treadmill. Only difference is that its not 1 continuous loop. The point is, the truck and conveyor belt could be doing 200mph in the opposite direction, the propeller still pushes the plane forward.

Sam.

P.S. Sorry about my English!

It's not your English but more your appreciation of science... :-0


Don't give up your trading day job... :cheesy:

 

[raysor]

We have established the wheels have no bearing.
We have established the plane goes nowhere fast.
We have established the belt conveys nothing.
We know it is better to travel than arrive.

What else is there?

 

[the blades]

What else is there?

We have established that far too many people have far too much time on their hands.

UTB

 

[trendie]

I suspect Skill Leverage is busy looking for that gun with 2 firing pins, to put himself out of this misery, rather than face another weekend and another teaser.

 

[Hotch]

Slowly slowly catchy monkey...

...can we at least all agree that given the wheels moving twice as fast as normal, and the conveyor belt is moving at the speed the plane would normally take off, that the plane takes off?

 

[raysor]

Slowly slowly catchy monkey...

...can we at least all agree that given the wheels moving twice as fast as normal, and the conveyor belt is moving at the speed the plane would normally take off, that the plane takes off?

NO!

 

[Atilla]

Slowly slowly catchy monkey...

...can we at least all agree that given the wheels moving twice as fast as normal, and the conveyor belt is moving at the speed the plane would normally take off, that the plane takes off?

Hotch!

What makes an aeroplane lift?

Wind! (Not hot air if I may add... :cheesy

What on earth has the movement of the wheels or rug got to do with it.

For an aeroplane to lift you need wind mate. Either by forward movement of plane or head on wind to give you total wind speed of probably 60-80knots I'd guess for a small light aircraft like that.

All this talk about speed of rug moving in one direction and speed of wheels being twice the speed of rug blah blah blah is absolute rubbish.

Conveyor belt? It's a bleedin table cloth for Gods sake. Get real. :cheesy:


What is the wind speed over the wings! Rest is absolute tosh.

 

[Hotch]

WTF mate?

Maybe I am incapable of expressing myself...

What I was trying to say was...

Can we agree that if the plane moves forward along the conveyor belt, that it takes off.

The argument I'm giving is not that the plane stays in the same place relative to a nearby tree, and just mysteriously moves upward. The argument is that it moves to the end of the conveyor belt as if it wasn't there.

But I'm trying to break it into small steps.

So...If the conveyor belt is OFF, and not moving at all, and the jet goes along it, does it take off?

 

[raysor]

WTF mate?

Maybe I am incapable of expressing myself...

What I was trying to say was...

Can we agree that if the plane moves forward along the conveyor belt, that it takes off.



So...If the conveyor belt is OFF, and not moving at all, and the jet goes along it, does it take off?

Yes and yes.
Unfortunately that breaks the premise of the question. The wheels must revolve at the same speed as the belt.
If the brakes were on and the belt moved forward at the same speed as the jet then the jet takes off and the wheels are revolving at the same speed as the belt (zero). If the belt is moving backwards somehow it's net speed forward must equal the speed of the jet, which seems, to me , impossible.
You can forget acceleration, lift etc.; if you can prove the plane moves forward, relative to the ground, then it is capable of taking off.

 

[Atilla]

Yes and yes.
Unfortunately that breaks the premise of the question. The wheels must revolve at the same speed as the belt.
If the brakes were on and the belt moved forward at the same speed as the jet then the jet takes off and the wheels are revolving at the same speed as the belt (zero). If the belt is moving backwards somehow it's net speed forward must equal the speed of the jet, which seems, to me , impossible.
You can forget acceleration, lift etc.; if you can prove the plane moves forward, relative to the ground, then it is capable of taking off.

I concur.

You could chain it to a post and stick a fan in front of it and you can still get it to lift off - if the wind speed over the winds is sufficiently fast flow. Wheels can turn at 4 x speed of rug being pulled away at 2 or even 8 x the speed of the wheels - makes not one jot of difference.

Flawed experiment imho poorly measured and executed based on theory - poorly demonstrated. Grade F.


As some other bloggers expressed - why has it taken us so long to get here...

Insanity of man... :clap:

 

[Hotch]

Calm down dear! It's only a commercial!

I swear we've been over this a hundred times; that the question may be worded poorly.

So ignore skill's wording for now

What if the conveyor moves backwards at the speed of the plane moving relative to the ground?

If you say that the movement cancels out, then you're in some paradox, because if the movement cancels out, then the plane isn't moving, so the conveyor isn't moving, which is nonsensical.

MY understanding, is that the conveyor is moving at the speed of the plane, and it's only effect is to "spin" the wheels around even faster.

Say you had a bike and you put it on a conveyor belt, if you turned the conveyor on the bike would move backwards but the wheels wouldn't spin. If you held the bike in place, the bike wouldn't move but the wheels would spin. Now say you push the bike forward, the wheels spin even faster, and the bike moves forward no?

Then it's a simple jump from bike to plane (maybe with one of those crazy failures of a flying machine powered by peddling in between).

P.S. Glad this has got more civilised

 

[raysor]

Imagine this: A cart with toothed wheels on a conveyor belt (with teeth) set at a 45 degree angle.
Whatever happens the cart must roll down the incline, regardless of what speed you apply to the belt.
However, surely the wheels must revolve faster than the belt? i.e. they would jump the cogs.

You can't say the wheels act independently of the axles etc. For each revolution of the wheel the plane must be moving the distance equal to the circumference.likewise the belt must move the same distance in the opposite direction.

 

[Atilla]

Calm down dear! It's only a commercial!

I swear we've been over this a hundred times; that the question may be worded poorly.

So ignore skill's wording for now

What if the conveyor moves backwards at the speed of the plane moving relative to the ground? 0 velocity. Plane remains at stand still.

If you say that the movement cancels out, then you're in some paradox, because if the movement cancels out, then the plane isn't moving, so the conveyor isn't moving, which is nonsensical. No it is not. You are in paradox here. Need further explanation. Here look carry out this experiment. Get a match box aeroplane with a dishcloth. Hold the plane with spinning wheels whilst pulling the dishcloth out underneath it. Energy is absorbed in the spinning wheels. Where is the paradox?

MY understanding, is that the conveyor is moving at the speed of the plane, and it's only effect is to "spin" the wheels around even faster. Ok this is my understanding too.

Say you had a bike and you put it on a conveyor belt, if you turned the conveyor on the bike would move backwards but the wheels wouldn't spin. If no force is applied to pedals yes! If you held the bike in place, the bike wouldn't move but the wheels would spin. Correct!Now say you push the bike forward, the wheels spin even faster, and the bike moves forward no? Back to square one. Yes but you are on the moving conveyor belt also taking you backwards. If belt moves 10mph backwards and you cycle at 10mph on the conveyor belt you are effectively man running on conveyor belt. Wheels spin at 10mph no different to if you were on tarmac. Bike and you cycling remain static on the same spot.

Then it's a simple jump from bike to plane (maybe with one of those crazy failures of a flying machine powered by peddling in between). No. I beg to differ. If belt moving back at 40 knots and plane moving forward at 80knots with head on wind at 20knots. Effective wind speed 60knots plane may take off. With no head wind effective wind speed 40knots. Plane moves forward but does not achieve lift wind speed.

P.S. Glad this has got more civilised

Always squire... Just a little frustrated at lack of progress. Forgive me my outbursts...

 

[MrGecko]

Skill, I understand you are a bit of a foodie, so I thought I would try and disrupt the thread with some ideas for recipies...

Tonight I have cooked a bit of an impromptu cassolet... no haricot beans and included toms... but not quite a casserole and certainly not a stew... anyway, here goes: serves one (skinny) single man over a six nations weekend:

6 x Chicken drumsticks
6 x Chicken thighs
2 x Carrot
2 x stick celery
4 x handful baby new potatoes / 2 tin haricot beans
6 clovesgarlic
2 red onion
2 tin chopped toms
2 empty tom tins of good quality chicken stock
2 sticks thyme
1 x 'horseshoe"chorizo


recipe:

in the le cruset... olive oil. heat. Brown chicken. remove

add diced chorizo. Simmer 5 mins.

Add aromatics (diced carrrot, 1cm pieces... celery 1cm pieces. peel onion, slice perpendicular to root and slice 0.5cm both sides).

cook until sweated , about 10 mins I reckon.

add 2 tins good quality chopped toms
add the same tin of proper chicken stock

stir and bring to the biol

Introduve the coloured chicken pieces to the top of the dish.. the biggest le cruset pan I have is about the size of a size 5 ball and weighs about twice a morgan pass developer. Try and keep the cloured side of the chicken at the top of the dish for presentaion purposes.

give it 90m+ at gas mark 5 (4 properly, but 5 to be safe).

eat with **** load of crusty bread and chilled white wine.




Alternatively, replace the chicken with salt cod (WASHED) and the potatoes with haricot beans...

all good yummy grub.

much love

G

p.s I'm eatin it now and its gorgeous.

Sh!t, I forgot; half the potatoes and bung them in with the toms. The garlic goes in with the aromatics.

 

[MrGecko]

NOTE: Bung the tyme in before it goes in the oven.... you might like to add a bayleaf, but beware of seasoning - the chorizo is probably enough salt for the toms (which of course LOVE salt). I find a few pepporcorns do the job, sans all additional salt (its always available on the table for those who require it)

 

[MrGecko]

And another thing:i f you do it with fish (any strong white fish will do), use veg stock rather than chicken.