On 28.11.2011 21:24, Henry Wilson DSc. wrote:
On Mon, 28 Nov 2011 11:16:55 -0800 (PST), Jerry
wrote:
On Nov 25, 5:16 pm, ..@..(Henry Wilson DSc.) wrote:
On Fri, 25 Nov 2011 22:49:47 +0100, "Paul B. Andersen"
The peculiarity is that if r is the distance from the hub
to the ground, the wheel will advance more than 2 pi r
per revolution.
How is that possible?
The sides of the tire are flexing.
Oh dear! I feel embarrassed reading this.
If you didn't understand it, you should indeed
be embarrassed.
Whenever you are told the simplest fact, you refuse to believe it.
Why is that?
You did not make clear whether you took into account the flattening of the
tyre when spcified the radius.
Any normal reader would take it to mean the uncompressed radius of the tyre.
Try reading the original problem statement again:
Inserting context:
The odometer/speedometer readings are much less dependent
on the tire pressure than one would be inclined to think.
That's because modern tires usually are steel-belted
radial tires, where the circumference of the tire is very
stable and little dependent on the pressure.
So when the wheel has made one revolution, it will have
advanced one circumference.
"The peculiarity is that if r is the distance from the hub
to the ground, the wheel will advance more than 2 pi r
per revolution.
How is that possible?
The sides of the tire are flexing."
Ralph's response:
"Oh dear! I feel embarrassed reading this.
No wonder you are silly enough to believe
everything Einstein said."
Lethal argument defending his response follows.
Taa-daa:
There is no mention of a car....just a wheel.
You are of course right, Ralph.
Nobody has ever mentioned a car.
When you started the discussion about to what degree
the tire pressure affects the odometer readings by stating:
"I assumed the odometer reading is also 2% high...but
I could be wrong. It also depends on the tyre pressure."
... you were obviously thinking of just a wheel with an odometer.
And we all know that for just a wheel with an odometer,
the odometer readings depend on the tire pressure.
So you were right:
The odometer reading depend on the tire pressure!
Right?
--
Paul, having fun
http://www.gethome.no/paulba/