This took me longer than it should have done to work out (in fact it was looking out the window of a plane as it was taking off that finally convinced me).Â Just to be sure though I waited for confirmation from my aeronautical engineer of a brother Nick.
The puzzle goes like this:
â€œImagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway. The conveyer belt is designed to exactly match the speed of the wheels, moving in the opposite direction. Can the plane take off?
â€œI say no, because the plane will not move relative the the ground and air, and thus, very little air will flow over the wings. However, other people are convinced that since the wheels of a plane are free spinning, and not powered by the engines, and the engines provide thrust against the air, that somehow that makes a difference and air will flow over the wing.â€
The guy behind me at the airport told his buddy that, in fact, the plane WOULD take off, and his buddy seemed to agree. Do we have any physicists in the audience?”
I got it via David Pogue, the best bit on his blog is the resulting argument.
:: Justin ::