I think you guys are thinking way too hard on this. Fixed engine planes do not accelerate up and therefore must be moving forward to generate lift. You have to make a big assumption from the original question..........the conveyor belt WILL EXACTLY match the speed of the wheels. The only way this can happen is it the resistance to move forward equals the force to move forward. If the plane actually moves forward......the wheels touching the conveyor belt will be turning at a faster rate than the conveyor belt.........but the original question tells us this is not the case, therefore we know the plane does not move forward. The plane must sit on it's wheels until it leaves the ground. If the plane wants to move forward even slightly a force opposing it will cancel it out..........by definition the conveyor will keep the plane stationary. What is this opposing force........rolling resistance, friction, cheater brembo brakes, magic.....who cares? That is another problem all together. The original question says the wheels CAN NOT turn faster than the conveyor. Solve the problem from here. Don't reinvent the wheel......punn intended. Can the plane take off if it is stationary in relation to the ground and there is no wind? A jet engine pulls and pushes air.........but will not LIFT until wind goes over the wing......no forward motion....no fly. If this is a big crazy prop that forced wind over the wing............then I'll buy the plane can lift off......without moving forward. It's all in how you interpret the question.........we are all making assumptions. But that's all I'm gonna say about that...........Gump out.
the wheels are not attatched to the plane they are attached to frictionless bearings that float on grease. wheels have not effect on the plane unless you apply pressure to them via a braking system that actually connect the plane to the wheels.
That equation is impossible, it just loops onto itself. But where the premise is weak is upon the first instant of acceleration. If the wheels turn then there is movement. Right? The plane takes off with the wheel bearings burning because they're turning at v = ∞ I'm sure this answer is somewhere else in this long thread. (Imagine a submarine instead of a plane if that helps)
Nope. Ok, let's say the plane is FLYING 10 feet off the ground with the landing gear up. You drop the landing gear onto a conveyor belt that is moving the same speed (opposite direction) as the plane. When the wheels touch, they will have to go twice the speed they will normally go on a runway, but will the plane all of a sudden stop? Um...no.
Look at it another way, the question says the conveyor turns the same speed as the wheels. In actuality, the speed and rpm of wheels are two different things. Wheels never have a single true "speed". Say you have a rolling wheel holding up a body (i.e. car), and the car is moving at some velocity. A point at the top of the wheel is moving twice as fast as the car's velocity, a point at the center of the wheel is moving at the car's velocity, and a point at the bottom is stationary. It's been mentioned before. The question is a matter of conflicting constraints and how those are interpreted (which is why the whole issue is still being debated). To satify one, the other can't be true. In order for the conveyor to move at the same "speed" as the wheels, the plane cannot move. That means the plane would not take off. However, there is nothing to keep the plane from moving, in which case the plane would take off, but the conveyor could not turn the same "speed" as the wheels.
it's already been said...but i'll say it again plane's fly because of lift....this is known as bernoulli's princple it's physics folks it's been around for years. so if the plan does not move forward creating a stream of air for the wings to "lift" then the damn thing don't fly. end of issue Thank you come again
How can the conveyor keep the plane from moving forward when the engines essentially push on air, not the ground?
because motion is releative...if the converyor is matching the speed of the wheels equal and opposite. then the overall displacement of the plane is 0
huhuhuhuhuhuhuhuhu Anyone remember, I'm dwivin in my caa I ton on da wadio I pool yu cwooooosah you say no
The Bernoulli equations relate the pressure and kinetic energy of a fluid. An example of this relation is lift. The issue is not what causes a plane to fly. The issue is whether the plane will move. Planes move because of thrust. Thrust is generated through some sort of prop or jet engine and is unrelated to the wheels. If this wasn't so, a plane would not be able to continue to fly once it is in the air. Since the conveyor is unable to counteract the thrust of the engines, physics says the plane will move. If the plane moves, the conveyor constraint is no longer valid. Once again, the question is flawed.
Just to be annoying: The popular explanation of lift "Students of physics and aerodynamics are taught that airplanes fly as a result of Bernoulli’s principle, which says that if air speeds up the pressure is lowered. Thus a wing generates lift because the air goes faster over the top creating a region of low pressure, and thus lift. This explanation usually satisfies the curious and few challenge the conclusions. Some may wonder why the air goes faster over the top of the wing and this is where the popular explanation of lift falls apart." from (http://www.allstar.fiu.edu/aerojava/airflylvl3.htm) Bernoulli's princile is also used to descripe "lift" when talking about airplanes Werd JON
How much could it cost to build a big conveyor belt? We have raised money before for motorcycle safety and this is proving to be equally as important of an issue.
No where does this state that it's a jet, just "a plane". Could be a glider, a cessna or a 747. So? This is irrelevant. The wheels are not locked if it's matching rotatation. If the wheels are turning in the direction that would take the plane "forward" to achieve lift, and the conveyor belt were rotating in the opposite direction, then the plane cannot lift off because it would remain stationary on the belt, regardless of speed of the wheels and belt. Again: So? Irrelevant No. So plane, jet, submarine does not make any difference. wind speed, mass, velocity, no mas. thank you for that little bit of entertainment.
