phipck Posted September 19, 2011 Report Share Posted September 19, 2011 i only recently discovered this chap through a friend of mine, but instantly i have been transfixed by his imagination and passion for what he did (unfortunatly he past away in the 80's) if you can keep up with his visual metophors he will open your mind with his intellegence and educate you without you realising, he has become quite quickly one of my heros, i wish to one day be as great minded as he was anyway, this video is a bit of a rollercoaster of logic with a nice little question at the end..... what do you reccon? (try to resist googling or youtubing it ) Please wait a few moments for Video to Load! Quote Link to comment Share on other sites More sharing options...
Tony Posted September 19, 2011 Report Share Posted September 19, 2011 My head hurts...... Answer to the question has to be gravity Quote Link to comment Share on other sites More sharing options...
phipck Posted September 19, 2011 Author Report Share Posted September 19, 2011 lol, my head didnt hurt so much just kinda fizzed for a bit ok, if gravity is your answer i can understand the logic and why it would not float away but if gravity is the only thing keeping it on the tracks what then stops it falling off them at a bend? Quote Link to comment Share on other sites More sharing options...
scorps Posted September 19, 2011 Report Share Posted September 19, 2011 lol, my head didnt hurt so much just kinda fizzed for a bit ok, if gravity is your answer i can understand the logic and why it would not float away but if gravity is the only thing keeping it on the tracks what then stops it falling off them at a bend? Ah ha...i know the answer coz my uncle worked for British Rail as an engineer but i wont give the answer away i can pm you the answer Quote Link to comment Share on other sites More sharing options...
Tony Posted September 20, 2011 Report Share Posted September 20, 2011 Staying on track on the bend would depend on it's speed. Quote Link to comment Share on other sites More sharing options...
phipck Posted September 20, 2011 Author Report Share Posted September 20, 2011 lol, my head didnt hurt so much just kinda fizzed for a bit ok, if gravity is your answer i can understand the logic and why it would not float away but if gravity is the only thing keeping it on the tracks what then stops it falling off them at a bend? Ah ha...i know the answer coz my uncle worked for British Rail as an engineer but i wont give the answer away i can pm you the answer no need to pm me, its the adventure of seeing people trying to figure it out that i quite enjoy watching, it took me some time and looking at trains in the real world to come to an answer which was almost correct Staying on track on the bend would depend on it's speed. could you expand your thinnking a little bit on that, im not sure where you are going with your idea? Quote Link to comment Share on other sites More sharing options...
Tony Posted September 20, 2011 Report Share Posted September 20, 2011 What keeps it on the track is weight -V- gravity, my point was there's a limit on the bend that could surpass gravity if speed and centrifugal lateral force was violated, basically tip over. Quote Link to comment Share on other sites More sharing options...
phipck Posted September 20, 2011 Author Report Share Posted September 20, 2011 i think i know where you are going with this and i think you are making the same assumptions i made, this then might be a pleasent suprise Please wait a few moments for Video to Load! Quote Link to comment Share on other sites More sharing options...
Tony Posted September 21, 2011 Report Share Posted September 21, 2011 Question wasn't what i thought originally but what he says makes perfect sense. Quote Link to comment Share on other sites More sharing options...
Sagitar Posted September 21, 2011 Report Share Posted September 21, 2011 Question wasn't what i thought originally but what he says makes perfect sense. It's a good explanation, especially for a train travelling on a straight track, but not entirely complete. The flange is not just a safety device, but when going around sharp bends, is often involved in keeping the train on the track. The rail is not just a flat topped bar, but is profiled to facilitate the movement of the wheel cone with increasing and decreasing centrifugal (or other lateral) force and to minimise the likelihood of the flange climbing up the rail when they come into contact. Rail engineers use a formula to calculate the relationship between lateral and vertical forces on the rail and I seem to recollect (though it's a long time ago since I studied it) that they generally aim to ensure that at the design limit, the vertical force is at least twice the lateral force. It's simply not true to say that you cannot go round a corner without a differential. Lots of quad-bikes do, though the experience may not be a good one and anyone who has heard the horrible metal-on-metal squealing that goes on when a train is negotiating the tight bends and sets of points that precede entry to a railway station has heard clear evidence of the slipping wheels and sliding flanges that result when trains go around bends that are too tight for the differential effect created by conical wheels. So, before you can answer the original question, you have to ask, "under what conditions". The ultimate answer is always going to be gravity, but that says nothing about the various mechanisms that apply. Quote Link to comment Share on other sites More sharing options...
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