johnnyknox Posted February 7, 2008 Share Posted February 7, 2008 No. Because the runway has already reacted and compenstated for the speed. Gaz...I can see your mind is made up mate. I'm going bed edit: but...they would move down the runway...the only force that the rocket would have to fight against, would be the friction in the wheels of the rollerskates against the treadmill...a force that the rocket would overcome and create forward movement. Night night Quote Link to comment Share on other sites More sharing options...
Rob Posted February 7, 2008 Share Posted February 7, 2008 Me too, but there'll be no "agree to disagree" here, because the laws of physics state that Gaz is wrong. http://en.wikipedia.org/wiki/Newton's_laws_of_motion Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 The action being exerted by the planes engine has no reaction from the belt, they are not related or connected in any way. The belt moves under its own power to match the spinning of the wheels. This isn't true. How is the force excerted on the belt/runway? By the wheels. That negates all other arguements as thats the only true way to tell how fast something is going. The main body won't go faster than the wheels and vice versa so at the end of it all the wheels are the only indicator of speed for the plane. It doesn't matter if you measure this against physical constants or landmarks, it's the truth. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 No, the runway "reacting" is a misnomer, it "reacts" in that it tries to match the reverse speed, which makes the wheels spin twice as fast, but it does not react against the thrust from the jet pack. It would because the violent shift of movement would cause a reaction. Quote Link to comment Share on other sites More sharing options...
JustGav Posted February 7, 2008 Share Posted February 7, 2008 Okay, lets break it down into some component parts... The plane requires a certain amount of wind speed in order to create enough lift to take off? In order to achieve this, the plane needs to be moving forward correct? Lets make an assumption here. In order for plane A to reach take off speed it needs to reach 80mph. Okay... next part In order to move a plane forward thrust is generated to move the plane forward to a sufficient speed to satisfy portion A. In order to push aircraft A forward thrust is generated providing a horizontal force parallel with belt. We have already however specified that any horizotal force will be matched with an equal and opposite force. The aircraft therefore does not move. Since the plane does not move, it does not satisfy section 1 and therefore will not take off and over rev the engines and go CABOOM If however the plane does not move due to the equal and opposite reaction to its position, it will remain static because not sufficient lift is generate because there is no airflow. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 Me too, but there'll be no "agree to disagree" here, because the laws of physics state that Gaz is wrong. http://en.wikipedia.org/wiki/Newton's_laws_of_motion This isn't true. How is the force excerted on the belt/runway? By the wheels. That negates all other arguements as thats the only true way to tell how fast something is going. The main body won't go faster than the wheels and vice versa so at the end of it all the wheels are the only indicator of speed for the plane. It doesn't matter if you measure this against physical constants or landmarks, it's the truth. Pour vous: ^ Quote Link to comment Share on other sites More sharing options...
Rob Posted February 7, 2008 Share Posted February 7, 2008 This isn't true. How is the force excerted on the belt/runway? By the wheels. That negates all other arguements as thats the only true way to tell how fast something is going. The main body won't go faster than the wheels and vice versa so at the end of it all the wheels are the only indicator of speed for the plane. It doesn't matter if you measure this against physical constants or landmarks, it's the truth. The only force being exerted on the runway/belt is the vertical vector of gravity and the weight of the plane. That is all. refer back to my post about the belt moving with the plane, so the wheels do not turn at all. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 The only force being exerted on the runway/belt is the vertical vector of gravity and the weight of the plane. That is all. refer back to my post about the belt moving with the plane, so the wheels do not turn at all. If the wheels don't turn, the plane isn't moving. Hence any kind of pressure from the air (lift) is negated. Quote Link to comment Share on other sites More sharing options...
Rob Posted February 7, 2008 Share Posted February 7, 2008 Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 Thanks for that. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 In our situation the plane isn't moving. It can't be. So how can it take off? Quote Link to comment Share on other sites More sharing options...
Rob Posted February 7, 2008 Share Posted February 7, 2008 If the wheels don't turn, the plane isn't moving. Hence any kind of pressure from the air (lift) is negated. If the belt matches the planes ground speed, the wheels don't turn, yet the plane still accelerates down the runway until it takes off. Get your head round that one. Quote Link to comment Share on other sites More sharing options...
JustGav Posted February 7, 2008 Share Posted February 7, 2008 Rob, you are correct if it was worded correctly and it said 'The conveyer belt tracks the wheel speed'... and that is real world bit which is accurate. HOWEVER the wording of this makes it very abigious and opens it up to debates like this Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 If the belt matches the planes ground speed, the wheels don't turn, yet the plane still accelerates down the runway until it takes off. Get your head round that one. How can it possibly accelerate if it's stationary? Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 If the belt matches the planes ground speed, the wheels don't turn, yet the plane still accelerates down the runway until it takes off. Get your head round that one. Oh and thats wrong anyway. If the belt matches the planes speed then it's always going to be zero, whatever the indicated airspeed. It can't take off because you'd have to be flying a multiple of total windspeed in a totally predictable environment to make this happen. Quote Link to comment Share on other sites More sharing options...
Rob Posted February 7, 2008 Share Posted February 7, 2008 How can it possibly accelerate if it's stationary? Because its NOT stationary, it's only stationary in relation to the belt, the belt is moving in perfect sync with the plane. ...and it doesn't matter if the belt tracks the aircraft exactly, or shoots the opposite way at 1000mph, the plane will always move down the belt and take off at arround 80mph ground speed 9using the light aircraft model) Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 Rob, you are correct if it was worded correctly and it said 'The conveyer belt tracks the wheel speed'... and that is real world bit which is accurate. HOWEVER the wording of this makes it very abigious and opens it up to debates like this Correct. But i'm arguing the toss simply because it doesn't. The reason: Ian C and the non-believers Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 Because its NOT stationary, it's only stationary in relation to the belt, the belt is moving in perfect sync with the plane. ...and it doesn't matter if the belt tracks the aircraft exactly, or shoots the opposite way at 1000mph, the plane will always move down the belt and take off at arround 80mph ground speed 9using the light aircraft model) It can't move anywhere if the speed of the plane and the ground speed going the other way match. It just can't. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 And yes, it's a stationary plane we are dealing with here, isn't it? Quote Link to comment Share on other sites More sharing options...
caseys Posted February 7, 2008 Share Posted February 7, 2008 Gaz, I do admire the fact you're a man that sticks to his guns when he believes wholeheartedly that he is correct. I'm off to bed, hopefully we'll all agree eventually! Quote Link to comment Share on other sites More sharing options...
Rob Posted February 7, 2008 Share Posted February 7, 2008 Non believers? You're not going to start a Python-esque religion are you? "and yay, on the seventh day the mighty belt of our lord did descend upon the land, and he saw that it was rubberised canvas, with stitch binded edging, and that it was a good belt" Quote Link to comment Share on other sites More sharing options...
Rob Posted February 7, 2008 Share Posted February 7, 2008 It can't move anywhere if the speed of the plane and the ground speed going the other way match. It just can't. But the ground speed is measured against stationary ground, not a moving belt. That's where you're confusing things. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 Gaz, I do admire the fact you're a man that sticks to his guns when he believes wholeheartedly that he is correct. I'm off to bed, hopefully we'll all agree eventually! If you examine the OP and the factors involved then I'm flattered you agree i'm right considering your previous posts. I'll agree that the plane can't go anywhere. Quote Link to comment Share on other sites More sharing options...
caseys Posted February 7, 2008 Share Posted February 7, 2008 Argh, I had to get this before I went to sleep.... Watch it! Quote Link to comment Share on other sites More sharing options...
Rob Posted February 7, 2008 Share Posted February 7, 2008 This is symbolic of your struggle against oppression... Quote Link to comment Share on other sites More sharing options...
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