no at those speed you'd spin a bearing in the wheels and blow up /jk but the roflcopter could fly while on a conveyor belt
________
The cigar boss

 

This was posted about two months ago at cc.com. And yes the plane would fly. The wheels would just be spining about twice as fast as they should. Prop acts againts the air not the ground.

 

As long as it is just standing there, no the plane will not fly. But then they add this:

OK so which direction? if the plane is moving in a direction that is "tail first" I think the answer remains, no it will not fly, infact unless the plane moves in a forward direction it is probably safe to say that the conditions needed for flight will not be met and the plane will not fly

So the conveyor will spin the wheels at twice the planes speed, OK, but we still don't know;
1) if the plane is moving in a direction that will allow it to fly, or for that matter
2) if the plane has reached or will reach a speed in excess if its stall velocity, which someone else pointed out is needed for the bernoulli effect and all the other aerodynamic conditions required for the plane to take off.

If the plane just ambles down the runway at 4 MPH with the conveyor tooling along at 8, the answer still is no, but if the plane is able to accelerate relative to the air around it to a speed which exceeds the plane's stall velocity, then yes the plane might fly.

The only correct answer to that question is;

"There is not sufficient information given to determine whether or not the plane will fly."

 

Nope. Sorry, it will fly. Unless someone can tell me exactly how a plane drives it's wheels. Most planes I know of can't do this. The thrust of the plane acts against the air around it not the ground. The plane will take off. Only it's gear will be turning faster that the ground speed indicated.

 

Bill, please read my post again and tell me how a plane flies just because it "moves in one direction" without neccesarily accelerating to a speed which exceeds its take-off velocity? You have to assume that it does to defend your statement that it will fly- but that information is NOT GIVEN in the problem statement.

 

how about we call the mythbusters and quit arguing
________
NO2 VAPORIZER REVIEW

 

The plane will not fly.

Even though the prop is generating thrust, there is no forward momentum. The forward momentum is what puts wind under/over it's wings.

Think of it this way, if you attached a rope to the tail of the plane and then pushed the engines all the way to max, do you think the plane would just jump up into the air and be anchored to the ground by the rope? No it would not. The props don't generate enough foot lbs of thrust. That's why planes have wings. Now if it were a rocket, then yes it would. Because a rocket doesn't need wings. It's got gobs of thrust to push it through the air.

So the bottom line is (besides me rambling) a plane needs foward momentum to take off. If the tires are spinning, there is no forward momentum. That's why planes have tires, wings, and engines,....to fly. You take just one of those things away and it won't fly (by itself).

A rocket will though.

Ok, there are exceptions. There's that tilt rotor aircraft. The offspray or whatever it is. But it's got the advantage tilting it's rotors and HUGE props. So it is able to lift straight up. That's a bit unconventional. We have to assume we're talking about conventional aircraft.

Ok, somebody shoot me now.

 

They are going to tell you, don't waste their time.

A plane that is standing still, will not fly because there is no air traveling over the wings. No air over wings....no lift.


Charlie