# Down wind faster than the wind

the pressure applied by the ruler is forcing the tire away. expulsion.

all that is need is a slight angle.

The friction of the ground provides the traction that rotates the wheels and causes them to roll along the ruler (that the ruler is moving makes no difference - if the ground were moving instead, the same effect would be seen).

If there were no ground friction, the entire apparatus would slide along with the ruler's horizontal push.
Does that help?

Thanks, yes. I think you are all saying the same thing.
The ruler is not acting to drive the large wheel, it is a force pushing the bottom wheels.

It's a good effect though.
When you first see it, it seems incredible.

So is it right?

kremmer said:
Thanks, yes. I think you are all saying the same thing.
I don't think John and I are saying quite the same thing.

My picture/feel does not require even a slight angle in the ruler - just friction between the upper wheel and the ruler as it is moved.

I am merely trying to provide an intuitive, especially a kinesthetic, feel, as a context for rpenner's equations of motion.

I don't think John and I are saying quite the same thing.

My picture/feel does not require even a slight angle in the ruler - just friction between the upper wheel and the ruler as it is moved.

I am merely trying to provide an intuitive, especially a kinesthetic, feel, as a context for rpenner's equations of motion.

Then I agree with John in one sense.....
The force is not on the upper wheel but the lower wheel.
And you in another.......
It does not matter how far the ruler moves

I'm sure I would agree with rpenner as well, but his analysis was beyond my level of understanding. ( That's not a criticism )

I don't think that anyone so far has agreed with the conclusions of the Youtube poster. Except myself initially, and I have changed my mind.

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kremmen said:
Then I agree with John in one sense.....
The force is not on the upper wheel but the lower wheel.
And you in another.......
It does not matter how far the ruler moves
I too regard the intuitive picture of the lower wheel being pushed - I picture an armature of little imaginary sticks tracing the path from the ruler to the ground through the lower wheel - as key.

But I think a perfectly horizontal motion of the ruler, no angle, will produce the motion of the wheels pictured.

I'm not sure what you meant by "how far the ruler moves".

Just that the ruler is acting as a force. It does not interact with the top wheel.
It doesn't matter how much it moves in relation to it, just how much energy it supplies to the whole system.
I thought that that was what you meant.

I think that the model does show that a force on a body in one direction can result in the motion of that body in the opposite direction.
What do you think?

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