The difference between the two problems, as I see it, is this:
Skill problem) Conveyor rolls anti-clockwise for a clockwise turn in the wheels
Bramble problem) Conveyor and Wheels both turn clockwise (anti-clockwise).
Whoa! That's not just semantics is it? I can see another 500 posts at least on this one...LOL
Let's get serious then and start being very specific in what we’re talking about.
Assume we are watching the 747 at the end of the conveyor belt. The end of the conveyor belt where the plane currently sits is to our extreme right as we stand perpendicular to the nose of the craft and off to the side of the conveyor. If it’s going to take off, it’s going to have to move from its starting point and head off to the left, along the conveyor belt. If it does that, the wheels of the plane will be rotating anti-clockwise from our perspective.
Case 1. Conveyor belt does not move and there is no constraint or special relationship between the wheels of the plane and the conveyor. The plane accelerates to 180mph airspeed, the wheels are rotating anti-clockwise from our perspective, the pilot raises the nose to get a bit of a draft going, and up it lifts. “Hooray!” the assembled (and by now very weary and dishevelled onlookers from t2w) cry.
This is pretty much what the 747s do all the time on normal runways.
The next two cases depart markedly from reality, in quite separate ways, so don’t get fooled.
Case 2.(Apparently named ‘Bramble Problem’) Same situation as Case 1 – the only difference being that the conveyor belt is now rigged to move TO THE RIGHT in precise and exact synchronisation with any indication of movement forward of the plane to the left. Clockwise/Anti-clockwise has no real application here, but if the conveyor could be considered to be the internal circumference of a really large wheel, a wheel so large it’s surface looked like a flat conveyor belt, then yes, it could be considered to be moving anti-clockwise too, but essentially, the conveyor is moving to our right, the plane would like to move to the left.
This is the scenario I’m solving for, the one I’ve always been solving for and the one, regardless of the number of variations Skills may have or may have wanted to give it, has been the one we’ve assumed to be the we’re all solving for subject to bit of fuzzy wording that we can presumably blame on his professors as it was their teaser – apparently, and if any previous version was ambiguous, the intent of Skills teaser was sufficient to warrant an assumption that what he eventually stated as the real teaser was the one we were all working on anyway.
Any forward motion of the plane at the exact moment it would have moved forward had it not had any other constraints operating, under a process not defined by Skills, but accepted by us as a given, has the conveyor moving backwards (to our left) to exactly the same extent.
The net result is there is no forward movement, therefore no airspeed, therefore no take off.
Round of applause and cheering from those who got it right, while the Flat-Earthers shuffle off mumbling and grumbling that that wasn’t what they meant anyway….
Case 3. ‘Skills Problem’. (LOL). You are suggesting is where the conveyor moves clockwise (to the left) as the planes wheels rotate anti-clockwise (plane moving to left). In this very new and very different scenario to any that have so far been offered and quite distinct from any Skills has ever suggested. He has always given that the conveyor is rigged to move OPPOSITE to the plane’s direction. It’s right there, still, in post #1.
Mr. G, I humbly suggest we’ve all be solving for the exact same scenario the whole time. Some got it right. Some didn’t.
