Can an airplane on a conveyor belt take off? (resolved)
published: 11/05/21, 11:29
Nothing to do with the subject, or almost, but this is the problem that is currently running on RS: will an airplane on a conveyor belt (which constantly cancels its ground speed) successfully take off?
If it is not a child's dream, it could be a problem with teenage physics (I am going to ask my son this evening ... 11 years old)!
Sorry it's automatic translation (I understood nothing after the "more clarity" )
Most of my friends are going to roll their eyes on this.
It happens regularly but the answer is not as simple as we think. Mainly because of a wording ambiguity.
The caption reads as follows:
Imagine that a 747 is sitting on a runway length conveyor belt. The conveyor belt is designed to exactly match the speed of the wheels, going in the opposite direction. Can the plane take off?
For the sake of clarity, I will add that the plane cranks up the throttle as it would for any other take-off. This should end SOME of the confusion.
Airplane folks (and critical thinkers) realize that airplanes move by pushing air, not by straining tires, so of course the plane can take off. But think about it. We usually measure the speed of tires by converting their rotary motion to linear speed, right? Let's do that here.
--- * Speed: based on tire rotation * ---
As the aircraft moves at 1 km / h, the conveyor belt moves at 1 km / h in the other direction. This causes the tire to accelerate immediately to 2 km / h, which makes the belt go to 3 km / h, which makes the tire go to 4 km / h, which ... The speed of the tires is heading towards infinity as the plane becomes tireless at around 1 km / h depending on the traction.
--- * Speed: based on a speedometer or GPS * ---
If you measure speed with a speedometer or GPS, you would probably be fine. The plane takes off and the tire speed will be twice as fast as the takeoff speed, which is probably only damaging (exceeding the design limits of RPM
Enough of that. Back to my regular schedule ...
You have 10 minutes!
If it is not a child's dream, it could be a problem with teenage physics (I am going to ask my son this evening ... 11 years old)!
Sorry it's automatic translation (I understood nothing after the "more clarity" )
Most of my friends are going to roll their eyes on this.
It happens regularly but the answer is not as simple as we think. Mainly because of a wording ambiguity.
The caption reads as follows:
Imagine that a 747 is sitting on a runway length conveyor belt. The conveyor belt is designed to exactly match the speed of the wheels, going in the opposite direction. Can the plane take off?
For the sake of clarity, I will add that the plane cranks up the throttle as it would for any other take-off. This should end SOME of the confusion.
Airplane folks (and critical thinkers) realize that airplanes move by pushing air, not by straining tires, so of course the plane can take off. But think about it. We usually measure the speed of tires by converting their rotary motion to linear speed, right? Let's do that here.
--- * Speed: based on tire rotation * ---
As the aircraft moves at 1 km / h, the conveyor belt moves at 1 km / h in the other direction. This causes the tire to accelerate immediately to 2 km / h, which makes the belt go to 3 km / h, which makes the tire go to 4 km / h, which ... The speed of the tires is heading towards infinity as the plane becomes tireless at around 1 km / h depending on the traction.
--- * Speed: based on a speedometer or GPS * ---
If you measure speed with a speedometer or GPS, you would probably be fine. The plane takes off and the tire speed will be twice as fast as the takeoff speed, which is probably only damaging (exceeding the design limits of RPM
Enough of that. Back to my regular schedule ...
You have 10 minutes!