At Ask Me Help Desk you can ask questions in any topic and have them
answered for free by our experts. To ask questions or participate in
answering them you must register for a free account. By registering you
will be able to:
Get free answers from experts in any of our 300+
topics.
I'm thinking this question had to been asked before, but I did a search and couldn't find anything on it. It's really bugging me, because I never could find out the right answer.
Suppose you have a jet airplane sitting on a runway. But this runway acts like a treadmill. The jet starts it's thrusters and for every mile an hour the Jet's wheels move forward, the treadmill moves a mile an hour in the opposite direction.
I've been thinking some more about this, and I want to revise my earlier answer. It's never too late to see the light! I had been thinking that the premise of the riddle was that the treadmill is designed to move at a speed that keeps the plane stationary. But what the riddle says "for every mile an hour the Jet's wheels move forward, the treadmill moves a mile an hour in the opposite direction" - thus if the plane (and its wheels) moves forward at 100 MPH, the treadmill moves the opposite direction at 100 MPH, which means the tires are spinning at the equivalent of 200 MPH. Hence the plane does move forward, and can take off. The tires will have had to spin at twice the rate as on a normal runway, but that's really the only difference.
ebaines, remember that the jet's engines are pushing against stationary air, irrespective of the tarmac, thereby producing thrust. The speed of the wheels on the landing gear don't enter into this equation.
ebaines, remember that the jet's engines are pushing against stationary air, irrespective of the tarmac, thereby producing thrust. The speed of the wheels on the landing gear don't enter into this equation.
Agreed. Previously I thought the premise of the riddle is that the treadmill moves fast enough to keep the plane stationary, and the only way that could be is if the friction between tires and treadmill would exactly counteract the thrust. Thus the treadmill would have to move at high enough speed to generate enough friction to counteract the jet's thrust. I now realize I had misinterpreted the wording of the riddle.
I'm thinking this question had to been asked before, but I did a search and couldn't find anything on it. It's really bugging me, because I never could find out the right answer.
Suppose you have a jet airplane sitting on a runway. But this runway acts like a treadmill. The jet starts it's thrusters and for every mile an hour the Jet's wheels move forward, the treadmill moves a mile an hour in the opposite direction.
Will this jet eventually take off? Thanks.
Rob
If the aircraft isn't moving forward into the wind, the wings will not receive airflow and the plane will not take off. The only way this is theoretically possible is with a severe headwind equal to the takeoff speed of the aircraft. But in this case, I would not want to be in the aircraft.
You're losing me. Any vehicle that is propelled by a drive train (i.e., it is driven by the wheels moving as opposed to thrust), theoretically, should remain stationary relative to someon standing next to the treadmill, correct?
This whole issue is one of thrust. Since a plane is not powered by it's wheels, they are in a sense, irrelevant. Technically, the plane should still move forward.
Picture a skateboard on the same treadmill with you at the opposite end (off the treadmill), holding a rope tied to the skateboard. Would you be able to pull the skateboard towards you?
Linear Mode
