Faster than the wind itself...

Thread Starter

cmartinez

Joined Jan 17, 2007
7,525
This apparent paradox is so mind blowing that I still can't grasp a full understanding of the physics involved:

 

nsaspook

Joined Aug 27, 2009
8,912
This apparent paradox is so mind blowing that I still can't grasp a full understanding of the physics involved:

10:58

"The propeller is not driving the wheels. (This is the key key.) In fact, the wheels are driving the propeller. The propeller is what is pushing the vehicle forward - which is why it can exceed the wind speed"
 

MrChips

Joined Oct 2, 2009
24,651
There are no laws of science that are broken here. I thought that it was fairly well explained in the video.
You cannot try to equate energy or wind speed and vehicle speed. You have to look at all the forces involved.
There is drag and friction on the vehicle. There is also lift created by the motion of the propeller.

I am a sailor and I teach sailing. I often have to explain how a sailboat can go faster than the wind even when travelling against the wind. The sail is an airfoil that creates lift. This lift pulls the boat forwards. It is the forces on the airfoil that is important, not the wind speed.

Similarly, it is the forces on the propeller blade that cause the vehicle to move faster, not the wind itself.
 

nsaspook

Joined Aug 27, 2009
8,912
He explains the working principle even better in this video:


Just the fact that he was willing to put up a $10,000 wager on it is absolutely epic!
A perfect example of the scientific method. I was shocked there was disagreement this as possible by the Prof .
 
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