OK perhaps a couple of points to make people think????
1. if you take the reference point as being the belt then it is stationary and only the wheel is moving (until you get to the end of the belt when you are in for a shock 😉
2. if you take the reference point as the center of the wheel then the center of the wheel remains stationary, the wheel rotates around it and the belt moves away from it.
3. if you take the reference point as the ground and the surface speed of the belt matches the surface speed of the wheel then although both the wheel and the belt are moving the center of the wheel remains in the same position with regards to the reference point on the ground.
Relative motion 🙂 and points of reference....
now one for Eviratec
take a skateboard, find a travelator that is on an angle and moving in the up direction (like the ones in shopping centers that allow you to take a trolley from level to level)
block the wheels so they cant turn and put the skateboard on the bottom of the travelator, what happens it goes to the top because the friction between the wheels and the travelator stops it from moving and the force is transfered to the skateboard taking it to the top.
now unblock the wheels, what happens??? the wheels turn and the skateborad remains at the bottom of the travelator, but hang on, I thought that the force was being transfered completely to the object???? lets try increasing the speed, will it go up, unless you get to the point where the wheel bearings seize or there is so much speed that the friction in the bearings becomes significant, it should stay at the bottom of the travelator.
Tony.
1. if you take the reference point as being the belt then it is stationary and only the wheel is moving (until you get to the end of the belt when you are in for a shock 😉
2. if you take the reference point as the center of the wheel then the center of the wheel remains stationary, the wheel rotates around it and the belt moves away from it.
3. if you take the reference point as the ground and the surface speed of the belt matches the surface speed of the wheel then although both the wheel and the belt are moving the center of the wheel remains in the same position with regards to the reference point on the ground.
Relative motion 🙂 and points of reference....
now one for Eviratec
take a skateboard, find a travelator that is on an angle and moving in the up direction (like the ones in shopping centers that allow you to take a trolley from level to level)
block the wheels so they cant turn and put the skateboard on the bottom of the travelator, what happens it goes to the top because the friction between the wheels and the travelator stops it from moving and the force is transfered to the skateboard taking it to the top.
now unblock the wheels, what happens??? the wheels turn and the skateborad remains at the bottom of the travelator, but hang on, I thought that the force was being transfered completely to the object???? lets try increasing the speed, will it go up, unless you get to the point where the wheel bearings seize or there is so much speed that the friction in the bearings becomes significant, it should stay at the bottom of the travelator.
Tony.
You're back on the 'wheels driving the plane' thing again.
Where are th eengines? or the fan on a skateboard? (I did like that experiment!)
Where are th eengines? or the fan on a skateboard? (I did like that experiment!)
Eviratec please read this carefully and really think about it!! don't just dismiss it because you "know you are right" If we never question our beliefs we can never attain enlightenment 🙂
OK and perhaps a different way of looking at the transference of force on the wheel and friction.
Take a stationary object sitting on the ground the oject has wheels, with the brakes applied it requires a very large amount of force to move the object (enough to break the friction of the wheels so that they start to skid). however if the breaks are not applied it requires a very small amount of force (comparitively) to make the object move, welcome to the engineering marvel of the wheel 😉
now if you think of the belt as just a variation of the ground and take your reference point as being on the belt as in my point 1 above then there is no difference compared to the object that is stationary on the ground (afterall if you took your reference point as being in space the ground is moving too).
Tony.
OK and perhaps a different way of looking at the transference of force on the wheel and friction.
Take a stationary object sitting on the ground the oject has wheels, with the brakes applied it requires a very large amount of force to move the object (enough to break the friction of the wheels so that they start to skid). however if the breaks are not applied it requires a very small amount of force (comparitively) to make the object move, welcome to the engineering marvel of the wheel 😉
now if you think of the belt as just a variation of the ground and take your reference point as being on the belt as in my point 1 above then there is no difference compared to the object that is stationary on the ground (afterall if you took your reference point as being in space the ground is moving too).
Tony.
Lostcause said:
hehehehe I'm not trying to say one way or the other, just making points about things that need to be considered. I long ago decided that there was no point trying to convince people one way or the other, only thing I think is that people should realise that the question is flawed, and can be interpreted differently ending in different outcomes 🙂
the skateboard example is because Eviratec is convinced that the belt is able to put enough force on the object to couneract the thrust from the engines and has nothing to do with the actual question.
edit: point 3 just illustrates the impossibility aspect of the question if real physics is used.
Tony.
Hi Tony,
Yes, she disagreed with me and left. To her great surprise, I was right and the plane took off. She should be in Texas by now. The rest of her party is stuck in Chicago. So in Chicago Eviratec would have been correct.
-Chris
Yes, she disagreed with me and left. To her great surprise, I was right and the plane took off. She should be in Texas by now. The rest of her party is stuck in Chicago. So in Chicago Eviratec would have been correct.
-Chris
wintermute said:
I too have given up on the question.......Ah, I see, you two ar ehaving it out then...carry on...I wont interupt again...
Hey Al,
Memes in the most Darwinian sense! Absolutely.
Most of us are done for. We just don't know it yet.
-Chris
Memes in the most Darwinian sense! Absolutely.
Most of us are done for. We just don't know it yet.
-Chris
Lostcause said:
not really having it out, I was thinking the same thing (as Eviratec) in my first post, but realised that my thinking was flawed 🙂 (ie I didn't really think about it at all!!!)
Tony.
Tony's right!
Many members have hurt themselves already. There may be a gap in the construction of DIY gear as people get themselves back together.
Back away from the computer slowly now .... easy ....
-Chris
Many members have hurt themselves already. There may be a gap in the construction of DIY gear as people get themselves back together.
Back away from the computer slowly now .... easy ....
-Chris
Same here Tony. It wasn't until the light bulb came on that I realized the plane was free to move independant of the wheels and that if the plane takes off at 250 km then the wheels will be moving at 500km at that point.
Tonight will be a better nights sleep.
Tonight will be a better nights sleep.
wintermute said:
THINKING! On the INTERNET? Do you know how rude that is? All you need a very strong opinion. Thought doesn't come into it.
Thats better!
🙂
OK Al,
I think you were the first one to nail this so the next obvious question is:
Are ducks actually swimming or simply paddling along as they float on the surface?
I think you were the first one to nail this so the next obvious question is:
Are ducks actually swimming or simply paddling along as they float on the surface?
Hmm, let me dig out my quantum physics textbooks, oh, and that paper I read the other day on chaotic wave formation in non-thixotropic fluid dynamics.
Hang on, my Chinese cookbook might have some useful info in it as well.
Hang on, my Chinese cookbook might have some useful info in it as well.
wintermute said:
Nope, he's bigger than I am! 🙂
:edit: and he probably has more Nail Guns as well...
OK Cal I think you should realise the complete evilness of your acts and do the honourable thing and put yourself in the sin bin for 2 days 😉
edit: and we should all send quickshift an invoice for our time 😉
Tony.
edit: and we should all send quickshift an invoice for our time 😉
Tony.
Hmmmm maybe I should request that I be put in the sin bin for a couple of days so that I can get some work done on my speakers!!! 😉
Tony.
Tony.
- Status
- Not open for further replies.